济南外国语学校华山校区2020年期中单元测试
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2020-2021济南外国语学校华山校区八年级数学下期中试卷及答案一、选择题1.小明搬来一架 3.5 米长的木梯,准备把拉花挂在 2.8 米高的墙上,则梯脚与墙脚的距离为( )A.2.7 米B.2.5 米C.2.1 米D.1.5 米2.下列二次根式中,最简二次根式是( )A.10B.12C.12D.83.如图,在矩形ABCD中,AB=2,BC=3.若点E是边CD的中点,连接AE,过点B作BF ⊥AE交AE于点F,则BF的长为()A.310B.310C.10D.354.如图,在水池的正中央有一根芦苇,池底长10尺,它高出水而1尺,如果把这根芦苇拉向水池一边,它的顶端恰好到达池边的水面则这根芦苇的长度是()A.10尺B.11尺C.12尺D.13尺5.下列计算正确的是()A.a2+a3=a5B.3221=C.(x2)3=x5D.m5÷m3=m26.函数y1x+中,自变量x的取值范围是()A.x>-1B.x>-1且x≠1C.x≥一1D.x≥-1且x≠17.下列各组数据中能作为直角三角形的三边长的是()A.1,2,2B.1,13C.4,5,6D.13,28.下列各组数是勾股数的是()A.3,4,5B.1.5,2,2.5C.32,42,52D345 9.如图是自动测温仪记录的图象,它反映了齐齐哈尔市的春季某天气温T如何随时间t的变化而变化,下列从图象中得到的信息正确的是( )A .0点时气温达到最低B .最低气温是零下4℃C .0点到14点之间气温持续上升D .最高气温是8℃10.如图,两张等宽的纸条交叉重叠在一起,重叠的部分为四边形ABCD ,若测得A ,C 之间的距离为12cm ,点B ,D 之间的距离为16m ,则线段AB 的长为( )A .9.6cmB .10cmC .20cmD .12cm11.如图所示,▱ABCD 的对角线AC ,BD 相交于点O ,AE EB =,3OE =,5AB =,▱ABCD 的周长( )A .11B .13C .16D .2212.为了研究特殊四边形,李老师制作了这样一个教具(如图1):用钉子将四根木条钉成一个平行四边形框架ABCD ,并在A 与C 、B 与D 两点之间分别用一根橡皮筋拉直固定,课上,李老师右手拿住木条BC ,用左手向右推动框架至AB ⊥BC (如图2)观察所得到的四边形,下列判断正确的是( )A .∠BCA =45°B .AC =BD C .BD 的长度变小 D .AC ⊥BD二、填空题13.如图,点E 在正方形ABCD 的边AB 上,若1EB =,2EC =,那么正方形ABCD 的面积为_.14.如图,E 、F 分别是平行四边形ABCD 的边AB 、CD 上的点,AF 与DE 相交于点P,BF 与CE 相交于点Q,若215APD S cm ∆=,225BQC S cm ∆=,则阴影部分的面积为__________2cm .15.小明想知道学校旗杆的高,他发现旗杆上的绳子垂到地面还多出1m ,当它把绳子的下端拉开旗杆4m 后,发现下端刚好接触地面,则旗杆的高为________16.如图,矩形纸片ABCD 中,已知AD =8,折叠纸片使AB 边与对角线AC 重合,点B 落在点F 处,折痕为AE ,且EF =3,则AB 的长为____.17.如图,正方形ABCD 中,AE=AB ,直线DE 交BC 于点F ,则∠BEF=_____度.18.如图,四边形ABCD 为菱形,8AC =,6DB =,DH AB ⊥于点H ,则BH =__________.19.已知矩形ABCD 如图,AB =4,BC =43,点P 是矩形内一点,则ABP CDP S S ∆∆+=______________.20.如图,已知▱ABCO 的顶点A 、C 分别在直线x =2和x =7上,O 是坐标原点,则对角线OB 长的最小值为_____.三、解答题21.如图,已知AC 是矩形ABCD 的对角线,AC 的垂直平分线EF 分别交BC 、AD 于点E 和F ,EF 交AC 于点O .(1)求证:四边形AECF 是菱形;(2)若AB =6,AD =8,求四边形AECF 的周长.22.如图,一个没有上盖的圆柱形食品盒,它的高等于24cm ,底面周长为20,cm 在盒内下底面的点A 处有一只蚂蚁,蚂蚁爬行的速度为2/cm s .(1)如图1,它想沿盒壁爬行吃到盒内正对面中部点B 处的食物,那么它至少需要多少时间?(盒的厚度和蚂蚁的大小忽略不计,下同)(2)如果蚂蚁在盒壁.上爬行了一圈半才找点B 处的食物(如图2),那么它至少需要多少时间?(3)假如蚂蚁是在盒的外部下底面的A处(如图3),它想吃到盒内正对面中部点B处的食物,那么它至少需要多少时间?23.计算:(311223-)233131÷+-+()()24.如图,在平行四边形ABCD中,过点D作DE AB⊥于点E,点F在边CD上,DF BE=,连接AF,BF.(1)求证:四边形BFDE是矩形;(2)若CF=3,BE=5,AF平分∠DAB,求平行四边形ABCD的面积.25.善于学习的小明在学习了一次方程(组),一元一次不等式和一次函数后,把相关知识归纳整理如下:(1)请你根据以上方框中的内容在下面数字序号后写出相应的结论:①;②;③;④;(2)如果点C的坐标为(1,3),那么不等式kx+b≤k1x+b1的解集为.【参考答案】***试卷处理标记,请不要删除一、选择题1.C解析:C【解析】【分析】仔细分析题意得:梯子、地面、墙刚好形成一直角三角形,梯高为斜边,利用勾股定理解此直角三角形即可.【详解】=2.1(米).故选C.【点睛】本题考查了勾股定理的应用.善于提取题目的信息是解题以及学好数学的关键.2.A解析:A【解析】【分析】根据最简二次根式的概念:(1)被开方数不含分母;(2)被开方数中不含能开得尽方的因数或因式,结合选项求解即可.【详解】A是最简二次根式,本选项正确.B==C2A=不是最简二次根式,本选项错误.故选A.【点睛】本题考查了最简二次根式的知识,解答本题的关键在于掌握最简二次根式的概念,对各选项进行判断.3.B解析:B【解析】【分析】根据S △ABE =12S 矩形ABCD =3=12•AE•BF ,先求出AE ,再求出BF 即可. 【详解】如图,连接BE .∵四边形ABCD 是矩形,∴AB=CD=2,BC=AD=3,∠D=90°,在Rt △ADE 中,22AD DE +2231+10, ∵S △ABE =12S 矩形ABCD =3=12•AE•BF , ∴BF=3105. 故选:B .【点睛】本题考查矩形的性质、勾股定理、三角形的面积公式等知识,解题的关键是灵活运用所学知识解决问题,学会用面积法解决有关线段问题,属于中考常考题型.4.D解析:D【解析】试题解析:设水深为x 尺,则芦苇长为(x+1)尺,根据勾股定理得:x 2+(102)2=(x+1)2, 解得:x=12,芦苇的长度=x+1=12+1=13(尺),故选D . 5.D解析:D【解析】分析:直接利用合并同类项法则以及幂的乘方运算法则、同底数幂的乘除运算法则分别计算得出答案.详解:A 、a 2与a 3不是同类项,无法计算,故此选项错误;B、,故此选项错误;C、(x2)3=x6,故此选项错误;D、m5÷m3=m2,正确.故选:D.点睛:此题主要考查了合并同类项以及幂的乘方运算、同底数幂的乘除运算,正确掌握相关运算法则是解题关键.6.D解析:D【解析】根据题意得:1010 xx+≥⎧⎨-≠⎩,解得:x≥-1且x≠1.故选D.7.D解析:D【解析】【分析】根据勾股定理的逆定理对各选项进行逐一分析即可.【详解】解:A、∵12+22=5≠22,∴此组数据不能作为直角三角形的三边长,故本选项错误;B、∵12+12=2≠)2,∴此组数据不能作为直角三角形的三边长,故本选项错误;C、∵42+52=41≠62,∴此组数据不能作为直角三角形的三边长,故本选项错误;D、∵12+2=4=22,∴此组数据能作为直角三角形的三边长,故本选项正确.故选D.【点睛】本题考查的是勾股定理的逆定理,熟知如果三角形的三边长a,b,c满足a2+b2=c2,那么这个三角形就是直角三角形是解答此题的关键.8.A解析:A【解析】【分析】欲判断是否为勾股数,必须根据勾股数是正整数,同时还需验证较小两数的平方和是否等于最大数的平方.【详解】A.32+42=52,是勾股数;B.1.5,2,2.5中,1.5,2.5不是正整数,故不是勾股数;C.(32)2+(42)2≠(52)2,不是勾股数;D2+22故选A.【点睛】本题考查了勾股数,解答此题要深刻理解勾股数的定义,并能够熟练运用.9.D解析:D【解析】【分析】根据气温T如何随时间t的变化而变化图像直接可解答此题.【详解】A.根据图像4时气温最低,故A错误;B.最低气温为零下3℃,故B错误;C.0点到14点之间气温先下降后上升,故C错误;D描述正确.【点睛】本题考查了学生看图像获取信息的能力,掌握看图像得到有用信息是解决此题的关键. 10.B解析:B【解析】【分析】作AR⊥BC于R,AS⊥CD于S,根据题意先证出四边形ABCD是平行四边形,再由AR=AS推出BC=CD得平行四边形ABCD是菱形,再根据根据勾股定理求出AB即可.【详解】作AR⊥BC于R,AS⊥CD于S,连接AC、BD交于点O.由题意知:AD∥BC,AB∥CD,∴四边形ABCD是平行四边形,∵两个矩形等宽,∴AR=AS,∵AR•BC=AS•CD,∴BC=CD,∴平行四边形ABCD是菱形,∴AC⊥BD,在Rt△AOB中,∵OA=12AC=6cm,OB=12BD=8cm,∴AB=2268=10(cm),故选:B.【点睛】本题主要考查菱形的判定和性质,证得四边形ABCD是菱形是解题的关键.11.D解析:D【解析】【分析】根据平行四边形性质可得OE是三角形ABD的中位线,可进一步求解.【详解】因为▱ABCD的对角线AC,BD相交于点O,AE EB,所以OE是三角形ABD的中位线,所以AD=2OE=6所以▱ABCD的周长=2(AB+AD)=22故选D【点睛】本题考查了平行四边形性质,熟练掌握性质定理是解题的关键.12.B解析:B【解析】【分析】根据矩形的性质即可判断;【详解】解:∵四边形ABCD是平行四边形,又∵AB⊥BC,∴∠ABC=90°,∴四边形ABCD是矩形,∴AC=BD.故选B.【点睛】本题考查平行四边形的性质.矩形的判定和性质等知识,解题的关键是熟练掌握基本知识,属于中考常考题型.二、填空题13.【解析】【分析】根据勾股定理求出BC根据正方形的面积公式计算即可【详解】解:由勾股定理得正方形的面积故答案为:【点睛】本题考查了勾股定理如果直角三角形的两条直角边长分别是ab斜边长为c那么a2+b2解析:3.【解析】【分析】根据勾股定理求出BC,根据正方形的面积公式计算即可.解:由勾股定理得,223BC EC EB=-=,∴正方形ABCD的面积23BC==,故答案为:3.【点睛】本题考查了勾股定理,如果直角三角形的两条直角边长分别是a,b,斜边长为c,那么a2+b2=c2.14.40【解析】【分析】作出辅助线因为△ADF与△DEF同底等高所以面积相等所以阴影图形的面积可解【详解】如图连接EF∵△ADF与△DEF同底等高∴S=S 即S−S=S−S即S=S=15cm同理可得S=S解析:40【解析】【分析】作出辅助线,因为△ADF与△DEF同底等高,所以面积相等,所以阴影图形的面积可解.【详解】如图,连接EF∵△ADF与△DEF同底等高,∴SADFV =S DEFV即SADFV −S DPFV=S DEFV−S DPFV,即S APDV =S EPFV=15cm2,同理可得S BQCV =S EFQV =25cm2,∴阴影部分的面积为S EPFV +S EFQV =15+25=40cm2.故答案为40.【点睛】此题考查平行四边形的性质,解题关键在于进行等量代换.15.【解析】【分析】根据题意画出示意图利用勾股定理可求出旗杆的高【详解】解:如图所示:设旗杆米则米在中即解得:旗杆的高为75米故答案为:75【点睛】本题考查了勾股定理的应用解答本题的关键是画出示意图熟练解析:7.5m【分析】根据题意画出示意图,利用勾股定理可求出旗杆的高.【详解】解:如图所示:设旗杆AB x =米,则(1)AC x =+米,在Rt ABC ∆中,222AC AB BC =+,即222(1)4x x +=+,解得:7.5x =.∴旗杆的高为7.5米故答案为:7.5.【点睛】本题考查了勾股定理的应用,解答本题的关键是画出示意图,熟练运用勾股定理. 16.6【解析】【分析】先根据矩形的特点求出BC 的长再由翻折变换的性质得出△CEF 是直角三角形利用勾股定理即可求出CF 的长再在△ABC 中利用勾股定理即可求出AB 的长【详解】解:∵四边形ABCD 是矩形AD=解析:6【解析】【分析】先根据矩形的特点求出BC 的长,再由翻折变换的性质得出△CEF 是直角三角形,利用勾股定理即可求出CF 的长,再在△ABC 中利用勾股定理即可求出AB 的长.【详解】解:∵四边形ABCD 是矩形,AD=8,∴BC=8,∵△AEF 是△AEB 翻折而成,∴BE=EF=3,AB=AF ,△CEF 是直角三角形,∴CE=8-3=5,在Rt △CEF 中,2222534CF CE EF =-=-=设AB=x ,在Rt △ABC 中,AC 2=AB 2+BC 2,即(x+4)2=x 2+82,解得x=6,则AB=6.故答案为:6.本题考查了翻折变换及勾股定理,熟知折叠是一种对称变换,它属于轴对称,折叠前后图形的形状和大小不变,位置变化,对应边和对应角相等是解答此题的关键.17.45【解析】【分析】先设∠BAE=x°根据正方形性质推出AB=AE=AD∠BAD=90°根据等腰三角形性质和三角形的内角和定理求出∠AEB和∠AED的度数根据平角定义求出即可【详解】解:设∠BAE=解析:45【解析】【分析】先设∠BAE=x°,根据正方形性质推出AB=AE=AD,∠BAD=90°,根据等腰三角形性质和三角形的内角和定理求出∠AEB和∠AED的度数,根据平角定义求出即可.【详解】解:设∠BAE=x°.∵四边形ABCD是正方形,∴∠BAD=90°,AB=AD.∵AE=AB,∴AB=AE=AD,∴∠ABE=∠AEB=12(180°﹣∠BAE)=90°﹣12x°,∠DAE=90°﹣x°,∠AED=∠ADE=12(180°﹣∠DAE)=12[180°﹣(90°﹣x°)]=45°+12x°,∴∠BEF=180°﹣∠AEB﹣∠AED=180°﹣(90°﹣12x°)﹣(45°+12x°)=45°.故答案为45.点睛:本题考查了三角形的内角和定理的运用,等腰三角形的性质的运用,正方形性质的应用,解答此题的关键是如何把已知角的未知角结合起来,题目比较典型,但是难度较大.18.【解析】【分析】由四边形ABCD是菱形AC=8BD=6可推出AD=AB=5由面积的可列出关于DH的方程求出DH的长度利用勾股定理即可求出BH的长度【详解】∵四边形ABCD是菱形AC=8BD=6∴AO解析:18 5.【解析】由四边形ABCD是菱形,AC=8,BD=6可推出AD=AB=5,由ABD∆面积的可列出关于DH的方程,求出DH的长度,利用勾股定理即可求出BH的长度.【详解】∵四边形ABCD是菱形,AC=8,BD=6,∴AO=4,OD=3,AC⊥BD,∴AD=AB=2234+=5,∵DH⊥AB,∴12⨯AO×BD=12⨯DH×AB,∴4×6=5×DH,∴DH=245,∴BH=222465⎛⎫- ⎪⎝⎭=185.【点睛】本题考查的考点是菱形的性质及勾股定理,灵活运用菱形的性质及勾股定理是解题的关键. 19.【解析】【分析】根据三角形的面积公式求出△APD和△BPC的面积相加即可得出答案【详解】过点P作MN∥AD交AB于点N交CD于点M如图∴AB∥CDAD∥BCAD=BC=AB=CD=4∴S△APB+S解析:83【解析】【分析】根据三角形的面积公式求出△APD和△BPC的面积,相加即可得出答案.【详解】过点P作MN∥AD,交AB于点N,交CD于点M.如图,∴AB∥CD,AD∥BC,AD=BC=AB=CD=4,∴S△APB+S△DPC=12×AB×PN+12CD×PM=12×4×PN +12×4×PM =12×4×(PM+PN)=1 2×4×.故答案为:【点睛】本题考查了矩形的性质和三角形的面积公式,主要考查学生的计算能力和观察图象的能力.20.9【解析】【分析】过点B作BD⊥直线x=7交直线x=7于点D过点B作BE⊥x轴交x轴于点E则OB=由于四边形OABC是平行四边形所以OA=BC又由平行四边形的性质可推得∠OAF=∠BCD则可证明△O解析:9【解析】【分析】过点B作BD⊥直线x=7,交直线x=7于点D,过点B作BE⊥x轴,交x轴于点E.则OB.由于四边形OABC是平行四边形,所以OA=BC,又由平行四边形的性质可推得∠OAF=∠BCD,则可证明△OAF≌△BCD,所以OE的长固定不变,当BE 最小时,OB取得最小值,即可得出答案.【详解】解:过点B作BD⊥直线x=7,交直线x=7于点D,过点B作BE⊥x轴,交x轴于点E,直线x=2与OC交于点M,与x轴交于点F,直线x=7与AB交于点N,如图:∵四边形OABC是平行四边形,∴∠OAB=∠BCO,OC∥AB,OA=BC,∵直线x=2与直线x=7均垂直于x轴,∴AM∥CN,∴四边形ANCM是平行四边形,∴∠MAN=∠NCM,∴∠OAF=∠BCD,∵∠OFA=∠BDC=90°,∴∠FOA=∠DBC,在△OAF和△BCD中,FOA DBC OA BCOAF BCD ∠=∠⎧⎪=⎨⎪∠=∠⎩,∴△OAF≌△BCD(ASA).∴BD=OF=2,∴OE=7+2=9,∴OB=22OE BE.∵OE的长不变,∴当BE最小时(即B点在x轴上),OB取得最小值,最小值为OB=OE=9.故答案为:9.【点睛】本题考查了平行四边形的性质、坐标与图形性质、全等三角形的判定与性质;熟练掌握平行四边形的性质,证明三角形全等是解决问题的关键.三、解答题21.(1)见解析;(2)25【解析】【分析】(1)根据四边相等的四边形是菱形即可判断;(2)设AE=EC为x,利用勾股定理解答即可.【详解】(1)证明:∵四边形ABCD是矩形∴AD∥BC,∴∠DAC=∠ACB,∵EF垂直平分AC,∴AF=FC,AE=EC,∴∠FAC=∠FCA,∴∠FCA=∠ACB,∵∠FCA+∠CFE=90°,∠ACB+∠CEF=90°,∴∠CFE=∠CEF,∴CE=CF,∴AF=FC=CE=AE,∴四边形AECF是菱形.(2)设AE=EC为x,则BE=(8-x)在Rt△ABE中,AE2=AB2+BE2,即x2=62+(8-x)2,解得:x=254,所以四边形AECF 的周长=254×4=25. 【点睛】 考查矩形的性质、线段的垂直平分线的性质、菱形的判定和性质、勾股定理等知识,解题的关键是灵活运用所学知识解决问题.22.(1)61s ;(2)329s ;(3)349s【解析】【分析】(1)从A 到B 有两种走法:从内壁直接爬过去和从盒子底部直接爬过去,画出展开图,求出AB 的长度,比较即可得出结果;(2)根据勾股定理解答即可;(3)要求圆柱体中两点之间的最短路径,最直接的作法,就是将正方体展开,作出B 关于边EF 的对称点D ,然后利用勾股定理求出AD 的长,再算出时间.【详解】(1)图1展开图,如图①、图②所示:图①中(直接沿着盒壁爬过去):261AB =图②中(沿底面直径爬过去再竖直爬上去):2012AB π=+2026112π<+Q261261t s ∴=÷=(2)如图:蚂蚁走过的最短路径为:223012629AB =+=,所用时间为:6292329s =;(3)如图2,作B 关于EF 的对称点D ,连接AD ,蚂蚁走的最短路程是AP+PB=AD ,由图可知,AC=10cm,CD=24+12=36(cm),2236101396+=,1396349s),从A到C349秒.【点睛】本题考查的是平面展开-最短路径问题,根据题意画出圆柱的侧面展开图,利用勾股定理求解是解答此题的关键.23.2 4 3【解析】【分析】根据二次根式的混合运算法则计算即可.【详解】原式=31123323÷÷+32-1=13313-+-=243.【点睛】本题考查了二次根式的混合运算,掌握各运算法则和平方差公式是关键.24.(1)见解析;(2)32【解析】【分析】(1)先求出四边形BFDE是平行四边形,再根据矩形的判定推出即可;(2)根据勾股定理求出DE长,即可得出答案.【详解】证明:(1)∵四边形ABCD是平行四边形,∴AB∥DC,∵DF=BE,∴四边形BFDE是平行四边形,∵DE ⊥AB ,∴∠DEB =90°,∴四边形BFDE 是矩形;(2)∵AF 平分∠DAB ,∴∠DAF =∠F AB ,∵平行四边形ABCD ,∴AB ∥CD ,∴∠F AB =∠DF A ,∴∠DF A =∠DAF ,∴AD =DF =5,在Rt △ADE 中,DE =()210h -=-,∴平行四边形ABCD 的面积=AB •DE =4×8=32, 【点睛】考查了平行四边形的性质,矩形的性质和判定等知识点,能综合运用定理进行推理是解此题的关键.25.(1)①kx +b =0,②11y kx b y k x b =+⎧⎨=+⎩,③kx +b >0,④kx +b <0;(2)x ≥1. 【解析】【分析】(1)①由于点B 是函数y=kx+b 与x 轴的交点,因此B 点的横坐标即为方程kx+b=0的解;②因为C 点是两个函数图象的交点,因此C 点坐标必为两函数解析式联立所得方程组的解;③函数y=kx+b 中,当y >0时,kx+b >0,因此x 的取值范围是不等式kx+b >0的解集; 同理可求得④的结论.(2)由图可知:在C 点右侧时,直线y=kx+b 的函数值要小于直线y=k 1x+b 1的函数值.【详解】解:(1)根据观察得:①kx +b =0,②11y kx b y k x b =+⎧⎨=+⎩,③kx +b >0,④kx +b <0. 故答案为:kx +b =0,11y kx b y k x b =+⎧⎨=+⎩,kx +b >0,kx +b <0; (2)∵点C 的坐标为(1,3),∴不等式kx +b ≤k 1x +b 1的解集为x ≥1.故答案为:x ≥1.【点睛】此题主要考查了一次函数与一元一次方程及一元一次不等式,二元一次方程组之间的内在联系.。
2020-2021济南外国语学校华山校区小学四年级数学下期中试卷及答案一、选择题1.把一个小数的小数点先向右移动三位,再向左移动两位,这个小数()。
A. 大小不变B. 扩大到原数的10倍C. 缩小到原数的10倍2.与3.01相等的数是()。
A. 3.1B. 3.010C. 3.001D. 3.10 3.把9.37先除以1000,再乘100,这时数字“3”应该在()上。
A. 个位B. 十分位C. 百分位D. 千分位4.与125+125×7相等的算式是()。
A. (125+1)×7B. 125×(7+1)C. (125+125)×(7+1)5.是天天10岁的生日蛋糕,从前面看它的形状是( )。
A. B. C.6.按照如图所示的表示方法,右图由7个立方体叠加的几何体,从正面观察,可以画出的平面图形是()A. B. C. D.7.越接近中午,太阳照射树的影子()。
A. 越短B. 越长C. 没有变化8.下面算式中先计算减法的是()。
A. 24+32-24B. 20+(65-60)C. 36-(19+9)9.计第(68-26)÷6时,要先算()A. 26÷6B. 68÷6C. 68-2610.下面的运算顺序与其他选项不同的一个算式是( )。
A. 2×12÷3B. 15+12-3C. 12+15÷3D. 36÷3×2 11.与87×101的计算结果相等的式子是()。
A. 87×100+1B. 87×100-1C. 87×100+87D. 87×100×1 12.25×23+25×76+25=25×(23+76+1)应用的是()A. 加法结合律B. 乘法结合律C. 乘法分配律二、填空题13.0.34里面有________个0.01,把1.36扩大到它的________倍是136。
2020-2021济南外国语学校华山校区九年级数学上期中试卷及答案一、选择题1.若关于x的一元二次方程4x2-4x+c=0有两个相等实数根,则c的值是()A.-1B.1C.-4D.42.方程x2+x-12=0的两个根为()A.x1=-2,x2=6B.x1=-6,x2=2C.x1=-3,x2=4D.x1=-4,x2=33.如图,将矩形 ABCD 绕点 A 顺时针旋转到矩形AB′C′D′的位置,旋转角为α(0°<α<90°).若∠1=112°,则∠α的大小是( )A.68°B.20°C.28°D.22°4.下列图形是我国国产品牌汽车的标识,在这些汽车标识中,是中心对称图形的是()A.B.C.D.5.如图在平面直角坐标系中,将△ABO绕点A顺时针旋转到△AB1C1的位置,点B、O分别落在点B1、C1处,点B1在x轴上,再将△AB1C1绕点B1顺时针旋转到△A1B1C2的位置,点C2在x轴上,将△A1B1C2绕点C2顺时针旋转到△A2B2C2的位置,点A2在x轴上,依次进行下去…若点A(32,0),B(0,2),则点B2018的坐标为()A.(6048,0)B.(6054,0)C.(6048,2)D.(6054,2)6.下列图形中,既是轴对称图形又是中心对称图形的是()A.B.C.D.7.如图,某小区计划在一块长为32m ,宽为20m 的矩形空地上修建三条同样宽的道路,剩余的空地上种植草坪.若草坪的面积为570m 2,道路的宽为xm ,则可列方程为( )A .32×20﹣2x 2=570 B .32×20﹣3x 2=570 C .(32﹣x )(20﹣2x )=570 D .(32﹣2x )(20﹣x )=5708.如图,△ABC 内接于⊙O ,∠C=45°,AB=2,则⊙O 的半径为( )A .1B .22C .2D .29.在Rt ABC ∆中,90ABC ∠=︒,:BC 2:3=AB , 5AC =,则AB =( ). A .52 B .10 C .5D .15 10.如图,将⊙O 沿弦AB 折叠,圆弧恰好经过圆心O ,点P 是优弧AMB 上一点,则∠APB 的度数为( )A .45°B .30°C .75°D .60°11.如图,直线y=kx+c 与抛物线y=ax 2+bx+c 的图象都经过y 轴上的D 点,抛物线与x 轴交于A 、B 两点,其对称轴为直线x=1,且OA=OD .直线y=kx+c 与x 轴交于点C (点C 在点B 的右侧).则下列命题中正确命题的是( )①abc>0; ②3a+b>0; ③﹣1<k <0; ④4a+2b+c<0; ⑤a+b<k .A .①②③B .②③⑤C .②④⑤D .②③④⑤12.如图,已知二次函数2y ax bx c =++(0a ≠)的图象与x 轴交于点A (﹣1,0),对称轴为直线x=1,与y 轴的交点B 在(0,2)和(0,3)之间(包括这两点),下列结论:①当x >3时,y <0;②3a+b <0; ③213a -≤≤-; ④248acb a ->;其中正确的结论是( )A .①③④B .①②③C .①②④D .①②③④二、填空题13.如图,将Rt ABC 绕直角顶点C 顺时针旋转90,得到DEC ,连接AD ,若25BAC ∠=,则BAD ∠=______.14.圆锥的底面半径为14cm ,母线长为21cm ,则该圆锥的侧面展开图的圆心角为_____ 度.15.如图,△ODC 是由△OAB 绕点O 顺时针旋转40°后得到的图形,若点D 恰好落在AB 上,且∠AOC =105°,则∠C = __.16.将抛物线y=﹣5x 2+1向左平移1个单位长度,再向下平移2个单位长度,所得到的抛物线的函数关系式为_____________ .17.一元二次方程()22x x x -=-的根是_____.18.在阳光中学举行的春季运动会上,小亮和大刚报名参加100米比赛,预赛分,,,A B C D 四组进行,运动员通过抽签来确定要参加的预赛小组,小亮和大刚恰好抽到同一个组的概率是_______.19.如图,O的半径为2,切线AB的长为23,点P是O上的动点,则AP的长的取值范围是_________.20.如图,是一个长为30m,宽为20m的矩形花园,现要在花园中修建等宽的小道,剩余的地方种植花草.如图所示,要使种植花草的面积为532m2,那么小道进出口的宽度应为米.三、解答题21.如图,在Rt△ABC中,∠C=90°,点D在AB上,以AD为直径的⊙O与BC相交于点E,且AE平分∠BAC.(1)求证:BC是⊙O的切线;(2)若∠EAB=30°,OD=3,求图中阴影部分的面积.22.已知关于x的方程(x﹣3)(x﹣2)﹣p2=0.(1)求证:方程总有两个不相等的实数根;(2)当p=2时,求该方程的根.23.某商场销售一批名牌衬衫,平均每天可销售20件,每件盈利40元.为了扩大销售,增加盈利,尽量减少库存,商场决定采取适当的降价措施.经调查发现,如果每件衬衫每降价5元,商场平均每天可多售出10件.求:(1)若商场每件衬衫降价4元,则商场每天可盈利多少元?(2)若商场平均每天要盈利1200元,每件衬衫应降价多少元?(3)要使商场平均每天盈利1600元,可能吗?请说明理由.24.“早黑宝”葡萄品种是我省农科院研制的优质新品种,在我省被广泛种植,邓州市某葡萄种植基地2017年种植“早黑宝”100亩,到2019年“卓黑宝”的种植面积达到196亩.(1)求该基地这两年“早黑宝”种植面积的平均增长率;(2)市场调查发现,当“早黑宝”的售价为20元/千克时,每天能售出200千克,售价每降价1元,每天可多售出50千克,为了推广宣传,基地决定降价促销,同时减少库存,已知该基地“早黑宝”的平均成本价为12元/千克,若使销售“早黑宝”每天获利1750元,则售价应降低多少元?25.关于x 的一元二次方程2210x x k ++-=有两个不相等的实数根.(1)求k 的取值范围;(2)当k 为正整数时,求此时方程的根.【参考答案】***试卷处理标记,请不要删除一、选择题1.B解析:B【解析】【分析】根据一元二次方程根的判别式可得:当△=0时,方程有两个相等的实数根;当△>0时,方程有两个不相等的实数根;当△<0时,方程没有实数根.【详解】解:根据题意可得:△=2(4)--4×4c=0,解得:c=1 故选:B .【点睛】本题考查一元二次方程根的判别式. 2.D解析:D【解析】试题分析:将x 2+x ﹣12分解因式成(x+4)(x ﹣3),解x+4=0或x ﹣3=0即可得出结论. x 2+x ﹣12=(x+4)(x ﹣3)=0, 则x+4=0,或x ﹣3=0, 解得:x 1=﹣4,x 2=3.考点:解一元二次方程-因式分解法3.D解析:D【解析】试题解析:∵四边形ABCD 为矩形,∴∠BAD=∠ABC=∠ADC=90°,∵矩形ABCD 绕点A 顺时针旋转到矩形AB′C′D′的位置,旋转角为α,∴∠BAB′=α,∠B′AD′=∠BAD=90°,∠D′=∠D=90°,∵∠2=∠1=112°,而∠ABD=∠D′=90°,∴∠3=180°-∠2=68°,∴∠BAB′=90°-68°=22°,即∠α=22°.故选D .4.B解析:B【解析】由中心对称图形的定义:“把一个图形绕一个点旋转180°后,能够与自身完全重合,这样的图形叫做中心对称图形”分析可知,上述图形中,A 、C 、D 都不是中心对称图形,只有B 是中心对称图形.故选B.5.D解析:D【解析】【分析】首先根据已知求出三角形三边长度,然后通过旋转发现,B 、B 2、B 4…每偶数之间的B 相差6个单位长度,根据这个规律可以求得B 2018的坐标.【详解】∵A (32,0),B (0,2), ∴OA =32,OB =2, ∴Rt △AOB 中,AB 22352()22+=, ∴OA +AB 1+B 1C 2=32+2+52=6, ∴B 2的横坐标为:6,且B 2C 2=2,即B 2(6,2),∴B 4的横坐标为:2×6=12, ∴点B 2018的横坐标为:2018÷2×6=6054,点B 2018的纵坐标为:2, 即B 2018的坐标是(6054,2).故选D .【点睛】此题考查了点的坐标规律变换以及勾股定理的运用,通过图形旋转,找到所有B点之间的关系是解决本题的关键.6.B解析:B【解析】【分析】根据轴对称图形与中心对称图形的概念求解.【详解】A、不是轴对称图形,是中心对称图形,故此选项错误;B、是轴对称图形,也是中心对称图形,故此选项正确;C、是轴对称图形,不是中心对称图形,故此选项错误;D、是轴对称图形,不是中心对称图形,故此选项错误;故选B.【点睛】此题主要考查了中心对称图形与轴对称图形的概念.轴对称图形的关键是寻找对称轴,图形两部分折叠后可重合,中心对称图形是要寻找对称中心,旋转180度后两部分重合.7.D解析:D【解析】【分析】六块矩形空地正好能拼成一个矩形,设道路的宽为xm,根据草坪的面积是570m2,即可列出方程.【详解】解:设道路的宽为xm,根据题意得:(32-2x)(20-x)=570,故选D.【点睛】本题考查的知识点是由实际问题抽象出一元二次方程,解题关键是利用平移把不规则的图形变为规则图形,进而即可列出方程.8.D解析:D【解析】【分析】【详解】解:连接AO,并延长交⊙O于点D,连接BD,∵∠C=45°,∴∠D=45°,∵AD 为⊙O 的直径,∴∠ABD=90°,∴∠DAB=∠D=45°,∵AB=2,∴BD=2,∴AD=22222222AB BD +=+=,∴⊙O 的半径AO=22AD =. 故选D .【点睛】 本题考查圆周角定理;勾股定理.9.B解析:B【解析】【分析】依题意可设2=AB x ,3BC x =,根据勾股定理列出关于x 的方程,解方程求出x 的值,进而可得答案.【详解】解:如图,设2=AB x ,3BC x =,根据勾股定理,得:222325+=x x ,解得5x =,∴10AB. 故选B.【点睛】本题考查了勾股定理和简单的一元二次方程的解法,属于基础题型,熟练掌握勾股定理是解题的关键.10.D解析:D【解析】【分析】【详解】作半径OC⊥AB于点D,连结OA,OB,∵将O沿弦AB折叠,圆弧较好经过圆心O,∴OD=CD,OD=12OC=12OA,∴∠OAD=30°(30°所对的直角边等于斜边的一半),同理∠OBD=30°,∴∠AOB=120°,∴∠APB=12∠AOB=60°.(圆周角等于圆心角的一半)故选D.11.B解析:B【解析】试题解析:∵抛物线开口向上,∴a>0.∵抛物线对称轴是x=1,∴b<0且b=-2a.∵抛物线与y轴交于正半轴,∴c>0.∴①abc>0错误;∵b=-2a,∴3a+b=3a-2a=a>0,∴②3a+b>0正确;∵b=-2a,∴4a+2b+c=4a-4a+c=c>0,∴④4a+2b+c<0错误;∵直线y=kx+c经过一、二、四象限,∴k<0.∵OA=OD,∴点A的坐标为(c,0).直线y=kx+c当x=c时,y>0,∴kc+c>0可得k>-1.∴③-1<k<0正确;∵直线y=kx+c与抛物线y=ax2+bx+c的图象有两个交点,∴ax2+bx+c=kx+c,得x 1=0,x 2=k b a- 由图象知x 2>1, ∴k b a->1 ∴k >a+b , ∴⑤a+b <k 正确,即正确命题的是②③⑤.故选B .12.B解析:B【解析】【分析】①由抛物线的对称性可求得抛物线与x 轴令一个交点的坐标为(3,0),当x >3时,y <0,故①正确;②抛物线开口向下,故a <0,∵12b x a=-=,∴2a+b=0.∴3a+b=0+a=a <0,故②正确;③设抛物线的解析式为y=a (x+1)(x ﹣3),则223y ax ax a =--,令x=0得:y=﹣3a .∵抛物线与y 轴的交点B 在(0,2)和(0,3)之间,∴233a ≤-≤.解得:213a -≤≤-,故③正确; ④.∵抛物线y 轴的交点B 在(0,2)和(0,3)之间,∴2≤c≤3,由248acb a ->得:248ac a b ->,∵a <0,∴224b c a -<,∴c ﹣2<0,∴c <2,与2≤c≤3矛盾,故④错误. 【详解】解:①由抛物线的对称性可求得抛物线与x 轴令一个交点的坐标为(3,0), 当x >3时,y <0,故①正确;②抛物线开口向下,故a <0, ∵12b x a=-=, ∴2a+b=0. ∴3a+b=0+a=a <0,故②正确;③设抛物线的解析式为y=a (x+1)(x ﹣3),则223y ax ax a =--,令x=0得:y=﹣3a .∵抛物线与y 轴的交点B 在(0,2)和(0,3)之间,∴233a ≤-≤.解得:2 13a-≤≤-,故③正确;④.∵抛物线y轴的交点B在(0,2)和(0,3)之间,∴2≤c≤3,由248ac b a->得:248ac a b->,∵a<0,∴224bca-<,∴c﹣2<0,∴c<2,与2≤c≤3矛盾,故④错误.故选B.【点睛】本题考查二次函数图象与系数的关系,结合图像,数形结合的思想的运用是本题的解题关键..二、填空题13.【解析】【分析】根据旋转的性质可得AC=CD再判断出△ACD是等腰直角三角形然后根据等腰直角三角形的性质求出∠CAD=45°由∠BAD=∠BAC+∠CAD 可得答案【详解】∵Rt△ABC绕其直角顶点C解析:70【解析】【分析】根据旋转的性质可得AC=CD,再判断出△ACD是等腰直角三角形,然后根据等腰直角三角形的性质求出∠CAD=45°,由∠BAD=∠BAC+∠CAD可得答案.【详解】∵Rt△ABC绕其直角顶点C按顺时针方向旋转90°后得到Rt△DEC,∴AC=CD,∴△ACD是等腰直角三角形,∴∠CAD=45°,则∠BAD=∠BAC+∠CAD=25°+45°=70°,故答案为:70°∘.【点睛】本题考查了旋转的性质、等腰直角三角形的判定与性质,熟练掌握相关性质并准确识图是解题的关键.14.240【解析】【分析】根据弧长=圆锥底面周长=28πcm圆心角=弧长180母线长π计算【详解】解:由题意知:弧长=圆锥底面周长=2×14π=28πcm扇形的圆心角=弧长×180÷母线长÷π=28π×解析:240【解析】【分析】根据弧长=圆锥底面周长=28πcm ,圆心角=弧长⨯180÷母线长÷π计算.【详解】解:由题意知:弧长=圆锥底面周长=2×14π=28πcm ,扇形的圆心角=弧长×180÷母线长÷π=28π×180÷21π=240°.故答案为:240.【点睛】此题主要考查弧长=圆锥底面周长及弧长与圆心角的关系,熟练掌握公式及关系是解题关键.15.【解析】【分析】先根据∠AOC 的度数和∠BOC 的度数可得∠AOB 的度数再根据△AOD 中AO=DO 可得∠A 的度数进而得出△ABO 中∠B 的度数可得∠C 的度数【详解】解:∵∠AOC 的度数为105°由旋转可解析:45︒【解析】【分析】先根据∠AOC 的度数和∠BOC 的度数,可得∠AOB 的度数,再根据△AOD 中,AO=DO ,可得∠A 的度数,进而得出△ABO 中∠B 的度数,可得∠C 的度数.【详解】解:∵∠AOC 的度数为105°,由旋转可得∠AOD=∠BOC=40°,∴∠AOB=105°-40°=65°,∵△AOD 中,AO=DO ,∴∠A=12(180°-40°)=70°, ∴△ABO 中,∠B=180°-70°-65°=45°,由旋转可得,∠C=∠B=45°,故答案为:45°.【点睛】本题考查旋转的性质,解答本题的关键是明确题意,找出所求问题需要的条件,利用旋转的性质解答.16.【解析】【分析】先确定出原抛物线的顶点坐标为(00)然后根据向左平移横坐标加向下平移纵坐标减求出新抛物线的顶点坐标然后写出即可【详解】抛物线的顶点坐标为(00)∵向左平移1个单位长度后向下平移2个单 解析:25(1)1y x =-+-【解析】【分析】先确定出原抛物线的顶点坐标为(0,0),然后根据向左平移横坐标加,向下平移纵坐标减,求出新抛物线的顶点坐标,然后写出即可.【详解】抛物线251y x =-+的顶点坐标为(0,0),∵向左平移1个单位长度后,向下平移2个单位长度,∴新抛物线的顶点坐标为(-1,-2),∴所得抛物线的解析式是()2511y x =-+-.故答案为:()2511y x =-+-.【点睛】本题主要考查的是函数图象的平移,根据平移规律“左加右减,上加下减”利用顶点的变化确定图形的变化是解题的关键. 17.x1=1x2=2【解析】【分析】整体移项后利用因式分解法进行求解即可得【详解】x(x-2)-(x-2)=0x-1=0或x-2=0所以x1=1x2=2故答案为x1=1x2=2【点睛】本题考查了解一元二解析:x 1=1, x 2=2.【解析】【分析】整体移项后,利用因式分解法进行求解即可得.【详解】x(x-2)-(x-2)=0,()()120x x --=,x-1=0或x-2=0,所以x 1=1, x 2=2,故答案为x 1=1, x 2=2.【点睛】本题考查了解一元二次方程——因式分解法,根据方程的特点熟练选择恰当的方法进行求解是关键.18.【解析】【分析】根据题意可以画出相应的树状图从而可以求得甲乙两人恰好分在同一组的概率【详解】如下图所示小亮和大刚两人恰好分在同一组的情况有4种共有16种等可能的结果∴小亮和大刚两人恰好分在同一组的概 解析:14【解析】【分析】根据题意可以画出相应的树状图,从而可以求得甲、乙两人恰好分在同一组的概率.【详解】如下图所示,小亮和大刚两人恰好分在同一组的情况有4种,共有16种等可能的结果, ∴小亮和大刚两人恰好分在同一组的概率是41164=, 故答案为:14. 【点睛】本题考查列表法与树状图法、用样本估计总体、条形统计图、扇形统计图,解答本题的关键是明确题意,找出所求问题需要的条件,利用数形结合的思想解答 19.【解析】【分析】连接OB 根据切线的性质得到∠OBA=90°根据勾股定理求出OA 根据题意计算即可【详解】连接OB∵AB 是⊙O 的切线∴∠OBA=90°∴OA==4当点P 在线段AO 上时AP 最小为2当点P 在解析:26AP ≤≤【解析】【分析】连接OB ,根据切线的性质得到∠OBA=90°,根据勾股定理求出OA ,根据题意计算即可.【详解】连接OB ,∵AB 是⊙O 的切线,∴∠OBA=90°,∴22AB OB +=4,当点P 在线段AO 上时,AP 最小为2,当点P 在线段AO 的延长线上时,AP 最大为6,∴AP 的长的取值范围是2≤AP≤6,故答案为:2≤AP≤6.【点睛】本题考查的是切线的性质、勾股定理,掌握圆的切线垂直于经过切点的半径是解题的关键.20.【解析】试题分析:设小道进出口的宽度为x 米依题意得(30-2x )(20-x)=532整理得x2-35x+34=0解得x1=1x2=34∵34>30(不合题意舍去)∴x=1答:小道进出口的宽度应为1米解析:【解析】试题分析:设小道进出口的宽度为x米,依题意得(30-2x)(20-x)=532,整理,得x2-35x+34=0.解得,x1=1,x2=34.∵34>30(不合题意,舍去),∴x=1.答:小道进出口的宽度应为1米.考点:一元二次方程的应用.三、解答题21.(1)证明见解析;(2)933 22π-.【解析】试题分析:()1连接OE.证明OE AC,从而得出∠OEB=∠C=90°,从而得证. ()2阴影部分的面积等于三角形的面积减去扇形的面积.试题解析:()1连接OE.∵AE平分∠BAC,∴∠CAE=∠EAD,∵OA=OE,∴∠EAD=∠OEA,∴∠OEA=∠CAE,OE AC∴,∴∠OEB=∠C=90°,∴OE⊥BC,且点E在⊙O上,∴BC是⊙O的切线.(2)解:∵∠EAB=30°,∴∠EOD=60°,∵∠OEB=90°,∴∠B=30°,∴OB =2OE =2OD =6,∴BE ==2OEB S = 扇形OED 的面积3π.2=3π.2-22.(1)证明见解析(2)x 1,x 2 【解析】【分析】(1)首先求出方程的根的判别式,然后得出根的判别式为非负数,得出答案;(2)将p=2代入方程,利用公式法求出方程的解.【详解】(1)证明:方程可变形为x 2﹣5x+6﹣p 2=0,△=(﹣5)2﹣4×1×(6﹣p 2)=1+4p 2.∵p 2≥0,∴4p 2+1>0,即△>0,∴这个方程总有两个不相等的实数根.(2)解:当p=2时,原方程为x 2﹣5x+2=0,∴△=25﹣4×2=17,∴,∴x 1x 2. 23.(1)商场每件衬衫降价4元,则商场每天可盈利1008元;(2)每件衬衫应降价20元;(3)不可能.理由见解析.【解析】【分析】(1)根据题意得到每天的销售量,然后由销售量×每件盈利进行解答;(2)利用衬衣平均每天售出的件数×每件盈利=每天销售这种衬衣利润列出方程解答即可;(3)同样列出方程,若方程有实数根则可以,否则不可以.【详解】 (1)410205⎛⎫⨯+ ⎪⎝⎭×(40-4)=1008(元). 答:商场每件衬衫降价4元,则商场每天可盈利1008元.(2)设每件衬衫应降价x 元,根据题意,得(40-x)(20+2x)=1200,整理,得x 2-30x+200=0,解得x 1=10,x 2=20,∵要尽量减少库存,∴x=20.答:每件衬衫应降价20元.(3)不可能.理由如下:令(40-x)(20+2x)=1600,整理得x 2-30x+400=0,∵Δ=900-4×400<0, ∴商场平均每天不可能盈利1600元.【点睛】此题主要考查了一元二次方程的应用,利用基本数量关系:平均每天售出的件数×每件盈利=每天销售的利润是解题关键.24.(1)该基地这两年“早黑宝”种植面积的平均增长率为40%.(2)售价应降低3元【解析】【分析】(1)设该基地这两年“早黑宝”种植面积的平均增长率为x ,根据题意列出关于x 的一元二次方程,求解方程即可;(2)设售价应降低y 元,则每天售出(200+50y )千克,根据题意列出关于y 的一元二次方程,求解方程即可.【详解】(1)设该基地这两年“早黑宝”种植面积的平均增长率为x ,根据题意得2100(1)196x +=解得10.440%x ==,2 2.4x =-(不合题意,舍去)答:该基地这两年“早黑宝”种植面积的平均增长率为40%.(2)设售价应降低y 元,则每天可售出(20050)y +千克根据题意,得(2012)(20050)1750y y --+=整理得,2430y y -+=,解得11y =,23y =∵要减少库存∴11y =不合题意,舍去,∴3y =答:售价应降低3元.【点睛】本题考查一元二次方程与销售的实际应用,明确售价、成本、销量和利润之间的关系,正确用一个量表示另外的量然后找到等量关系是列出方程的关键.25.(1)k <2(2)120,2x x ==-【解析】【分析】(1)根据一元二次方程根的判别式与根的关系列出不等式即可求出k 的取值范围; (2)根据(1)中的k 的取值范围和k 为正整数得出k 的值,再解方程即可,【详解】(1)∵关于x 的一元二次方程有两个不相等的实数根,∴()22410k ∆=-->, =8-4k >0.,∴2k <;(2)∵k 为正整数,∴k =1,解方程220x x +=得,120,2x x ==-.【点睛】本题考查了一元二次方程根的判别式、解一元二次方程.利用一元二次方程根的判别式与根的关系列出不等式是解题的关键.。
2020年济南外国语学校高三英语期中考试试题及答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项ASevenhugs HugOneDo you want to improve the quality of your sleep? Sevenhugs has created HugOne that tracks different sleep patterns to help families consistently rest better. There are dozens of devices and tools devoted to monitoring the sleep. But, HugOne is the world’s first family smart home sleep system, which integrates a calculation rule for sleep patterns of children and adults.HugOne is a well-designed product, full of a sense of science and technology. It connects to a number of smaller sensors called “minihugs”, which are placed on the edge of each bed. They monitor the sleep patterns and other data coming from the person sleeping in that bed. The data arethen sent to an app on the smartphone.● The benefits of HugOne include:* Having a smart alarm clock on the app as HugOne learns your sleep cycle and automatically sets and sounds to when the best moment in your sleep cycle is identified.* Monitoring temperature and humidity in your bedroom as well as indoor air quality for the main living space.* Linking with smart lamps and thermostats, allowing users to fall asleep with sunset light and preferred nighttime temperatures, and wake up to sunrise light and preferred daytime temperatures.* Ensuring safety from electronic transmissions when you sleep-when the minihug senses a presence in bed, it shuts off its electronic transmissions and starts recording sleep data and sending them to the app.● The following are selected from customers’ comments:I prefer HugOne, since it’s convenient to use. I simply place the minihug in the corner of my bed under the sheet and it goes to work monitoring my sleep cycle. It’s really good.—Robert Compton● HugOne available for purchase includes:I think HugOne is a humanized product. It’s shareable, and I’ve connected eight minihugs to the HugOne base in my house. All my family members think highly of it.—Chris HanawaltHugOne will provide maximum protection for your sleep. If you want to get more detailed information, please call the sellers at 1-800-576-1899 or .Style: Sleep Tracking System+2 Sleep SensorsColour: Blue+Rose1. How does HugOne effectively work?A. It controls sleep patterns automatically.B. It creates smart systems for a better sleep.C. It collects sleep data through the minihugs.D. It makes a calculation of the data sensors need.2. According to the passage, HugOne can ______.A. adjust temperature, humidity and air quality in bedroomsB. update the sleep cycles by aid of an alarm clock on the appC. record sleep data when there are electronic transmissions in bedD. help users fall asleep and wake up naturally with preferred temperatures3. The passage is made more believable by ______.A. providing statisticsB. drawing a comparisonC. giving a demonstrationD. using recommendationsBDoctors are known to be terrible pilots. They don’t listen because they already know it all, I was lucky: I became a pilot in 1970, almost ten years before I graduated from medical school. I didn’t realize then, but becoming a pilot makes me a better surgeon. I loved flying. As 1 flew bigger, faster planes, and in worse weather, I learned about crew resource management (机组资源管理), or CRM, a new idea to make flying safer. It means that crew members should listen and speak up for a good result, regardless of positions.I first read about CRM in 1980. Not long after that, an attending doctor and I were flying in bad weather. The controller had us turn too late to get our landing ready. The attending doctor was flying; I was safety pilot. He was so busy because of the bad turn, he had forgotten to put the landing gear (起落架) down. He was a better pilot—and my boss—so it felt unusual to speak up. But I had to: Our lives were in danger. I put aside my uneasiness sand said, we need to put the landing gear down now! That was my first real lesson in the power of CRM, and I’ve used it in the operating room ever since.CRM requires that the pilot/surgeon encourage others to speak up. It further requires that when opinions arefrom the opposite, the doctor doesn’t overreact, which might prevent fellow doctors from voicing opinions again. So when I’m in the operating room, I ask for ideas and help from others. Sometimes they’re not willing to speak up. But I hope that if I continue to encourage them, someday someone will keep me from landing gear up.4. What does the author say about doctors in general?A. They like flying by themselves.B. They are quick learners of CRM.C. They pretend to be good pilots.D. They are unwilling to take advice.5. The author deepened his understanding of the power of CRM when .A. his boss landed the plane too lateB. he was in charge of a flying taskC. he saved the plane by speaking upD. his boss operated on a patient6. In the last paragraph landing gear up probably means .A. following flying requirementsB. making a mistake that may cost livesC. listening to what fellow doctors sayD. overreacting to different opinions7. Which of the following can be the best title for the text?A. CRM: A New Way to Make Flying SafeB. A Pilot-Turned DoctorC. The Making of a Good PilotD. Flying Makes Me a Better DoctorCThis year researchers expect the world to snap 1.35 trillion photographs, or about 3.7 billion per day. All those pixels (像素) take up a lot of room if they are stored on personal computers or s phones, which is one reason why many people store their images in the cloud. But unlike a hard on drive which can be encrypted to protect its data, cloud storage users have to trust that a tech platform will keep their private pictures safe. Now a team of Columbia University computer scientists has developed a tool to encrypt (加密) images stored on many popular cloud services while allowing authorized users to browse and display their photographs as usual.Malicious (恶意的) attempts to access or leak cloud-based photographs can expose personal information. In November 2019, for example, a bug in the popular photograph storage app Google Photos mistakenly shared some users' private videos with strangers. Security experts also worry about employees at cloud storage companies on purpose accessing users' images.So the Columbia researchers came up with a system called Easy Secure Photos (ESP), which they presented at a recent conference. “We wanted to see if we could make it possible to encrypt data while using existing services,” says computer scientist Jason Nieh, one of the developers of ESP. “Everyone wants to stay with Google Photos and not have to register on a new encrypted-image cloud storage service.”To overcome this problem, they created a tool that preserves blocks of pixels but moves them around to effectively hide the photograph. First, ESP's algorithm (算法) divides a photograph into three separate files, each one containing the image's red, green or blue color1 data. Then the system hides the pixel blocks around among these three files (allowing a block from the red file, for instance, to hide out in the green or blue ones). But the program does nothing within the pixel blocks, where all the image processing happens. As a result, the files remain unchanged images but end up looking like grainy black-and-white ones to anyone who accesses them without the decryption (解密) key.8. What's probably the main purpose for people to store images in the cloud?A. To save storage room.B. To make photos beautiful.C. To try a new storage way.D. To keep their privacy safe.9. Why might employees in cloud storage companies be distrusted by experts?A. They sell users' passwords.B. They have invented new tools.C. They often let out personal information.D. They may steal a glance at users' images.10. What's the advantage of ESP?A. It can provide clear images.B. It can decrease the upload time.C. It can classify images automatically.D. It can encrypt data on the original platform.11. What does paragraph 4 mainly talk about?A. Method of decryption.B. Image-processing technique.C. Separate files of images.D. Data analysisof color1 s.DMost people around the world are right-handed. This also seems to be true in history. In 1799, scientists studied works of art made at different times from 1,500 B.C. to the 1950s. Most of the people shown in these works are right-handed, so the scientists guessed that right-handedness has always been common through history. Today, only about 10% to 15% of the world’s population is left-handed.Why are there more right-handed people than left-handed ones? Scientists now know that a person’s two hands each have their own jobs. For most people, the left hand is used to find things or hold things. The right hand is used to work with things. This is because of the different work of the two sides of the brain. The right side of the brain, which makes a person’s hands and eyes work together, controls the left hand. The left-side of the brain, which controls the right hand, is the centre for thinking and doing problems. These findings show that more artists should be left-handed, and studies have found that left-handedness is twice as common among artists as among people in other jobs.No one really knows what makes a person become right-handed instead of left-handed. Scientists have found that almost 40% of the people become left-handed because their main brain is damaged when they are born. However, this doesn’t happen to everyone, so scientists guess there must be another reason why people become left-handed. One idea is that people usually get right-handed from their parents. If a person does not receive the gene(基因) for right-handedness, he / she may become either right-handed or left-handed according to the chance and the people they work or live with.Though right-handedness is more common than left-handedness, people no longer think left-handed people are strange or unusual. A long time ago, left-handed children were made to use their right hands like other children, but today they don’t have to.12. After studying works of art made at different times in history, the scientists found _______.A. the art began from 1,500B.C.B. the works of art ended in the 1950sC. most people shown in the works of art are right-handedD. most people shown in the works of art are left-handed13. What is the left hand for most people used to do?A. It’s used to find or hold things.B. It’s used to work with things.C. It’s used to make a person’s eyes work together.D. It’s the centre for thinking and doing problems.14. According to the passage, which of the following is NOT true?A. No one really knows what makes a person become right-handed.B. Left-handedness is cleverer than right-handedness.C. Today children are not made to use their right hands only.D. Scientists think there must be some reason why people become left-handed.15. The best title for this passage is _______.A. Scientists’ New InventionsB. Left-handed PeopleC. Which HandD. Different Brains, Different Hands第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
山东省济南外国语学校第一学期高一期中考试语文试题(时间100分钟,满分120分)第Ⅰ卷(选择题共30分)一、(30分,每小题3分)1、下列各组词语中加点字的读音全部正确的一组A 提.(dī)防装订.(dīng)相形见绌.(chù)引吭.高歌(háng)B 缜.(zhēn)密客栈.(zhàn)载.(zài)歌载舞怏.(yāng)怏不乐C 札.(zhá)记症.(zhēng)结心宽体胖.(pán)潜.(qián)移默化D 横.(héng)祸聒.(guō)噪供.(gōng)不应求徇.(xún)私舞弊2、下列各组词语中,没有错别字的一组是A 竦身永决弥望延口残喘B 丰姿袅娜诅咒隐约其辞C 幽僻萧索宁秘豁然开朗D 蹉跎幅射禁锢情随事迁3、将下列词语依次填入各句横线处,最恰当的一组是①多种形式的岗位培训改变了人们只在学校接受教育的状况,一个人离开学校并不意味着学习的。
②由于环境污染日趋严重和一些人为的原因,近几年,著名的阿尔巴斯白山羊绒的品质正在逐步地。
③当年的嘉祥武氏乃钟鸣鼎食、诗书翰墨之族,而今却见不到雕梁画栋,听不到丝竹管弦,这里曾有的繁华与尊荣都在历史的尘埃中,只有那些断碑废垣上的石刻还残存着对历史的记忆。
A终止退化湮没B中止退化淹没C终止蜕化湮没D中止蜕化淹没4下列句子中,加点成语使用恰当的一句是A 安金鹏的母亲卖了家中唯一值钱的牛给儿子凑学费,真是心劳日拙....。
B 田世国为使患上尿毒症的母亲延续生命献出了自己健康的肾,让天下所有的母亲收获慰藉,让那些不肖子孙....汗颜无地。
C 王全书同志的著作集《感悟中原》即将出版,这是他多年含辛茹苦的经验结集,也是他长期惨淡经...营.的成果。
D 现在电子词典种类五花八门,功能良莠不齐....,选购到真正让人满意的产品并不容易。
5、下列句子中没有语病的一句是A 巴菲特以纯粹的“投资人”身份,跻身世界富豪排行榜榜眼,的确堪称奇才,不过在华尔街并非没有先例。
山东省济南外国语学校2020高二英语上学期期中模块考试试题无答案满分:150分; 时间:120分钟第Ⅰ卷(选择题,共 100分)第一部分听力(共两节,满分30分)第一节(共5小题;每小题1.5分,满分7.5分)听下面5段对话,每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. Where does the woman have to get off?A. At the Bank of China.B. At the post office.C. At the next stop.2. Why does the man refuse the woman?A. He doesn’t have a car.B. He will be using his car.C. She doesn’t drive.3. Where does the woman want to go?A. The Grand Hotel.B. The shopping center.C. The traffic light.4. How is the woman going home?A. In a car.B. By bus.C. On foot.5. How many friends can the girl invite?A. Four or five.B. Two or three.C. Two or four.第二节(共15小题;每小题15分,满分22.5分)听下面5段对话或独白。
每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题给出5秒钟的作答时间。
每段对话或独白读两遍。
听第6段质料,回答第6至7题。
2020-2021济南外国语学校华山校区小学二年级数学下期中试卷及答案一、选择题1.一支钢笔的价钱是6元,李老师用54元可以买()支。
A. 9B. 8C. 482.如果□×7=28,那么□里应填()。
A. 21B. 4C. 113.根据算式填空:(1)35 5=40,应填()A.+B.-C.×D.÷(2)16 8=2,应填()A.+B.-C.×D.÷(3)3 8=24,应填()A.+B.-C.×D.÷(4)24 8=16,应填()A.+B.-C.×D.÷4.图案是从下列()剪下来的。
A. B. C.5.时针围绕钟面中心,旋转()才能从6:00走到9:00。
A. 90°B. 180°C. 360°D. 120°6.计算与6÷6用同一句口诀的算式是()。
A. 6×6B. 6+6C. 6÷17.24÷3=8读作:()A. 24除以3等于8B. 24除3等于8C. 3除以24等于88.30÷6=5,读作()。
A. 30除以6等于5B. 30除以5等于69.下面是某年级(二)班同学对水果的爱好情况统计表,喜欢()水果的人数最多。
A. 苹果B. 梨C. 香蕉D. 桃10.按邮票的分值来分可以分为几类?()A. 3类B. 2类C. 4类11.下列不是轴对称图形的是()。
A. B. C.12.李兵和王芳做“石头、剪刀、布”的游戏。
下面是李兵画“正”字记录的自己游戏的结果。
那么王芳赢了()次。
A. 14B. 6C. 8二、填空题13.5的8倍是________,42是7的________倍。
14.电梯上升属于________现象,车轮运动属于________现象。
15.风扇扇叶的转动是________现象;推箱子是________现象。
2020-2021济南外国语学校华山校区九年级数学下期中试卷及答案一、选择题1.已知反比例函数y =﹣6x,下列结论中不正确的是( ) A .函数图象经过点(﹣3,2)B .函数图象分别位于第二、四象限C .若x <﹣2,则0<y <3D .y 随x 的增大而增大 2.如图,123∠∠∠==,则图中相似三角形共有( )A .1对B .2对C .3对D .4对 3.如图,用放大镜看△ABC ,若边BC 的长度变为原来的2倍,那么下列说法中,不正确的是( ).A .边AB 的长度也变为原来的2倍;B .∠BAC 的度数也变为原来的2倍; C .△ABC 的周长变为原来的2倍;D .△ABC 的面积变为原来的4倍; 4.如图,已知直线a ∥b ∥c ,直线m 、n 与直线a 、b 、c 分别交于点A 、C 、E 、B 、D 、F ,AC=4,CE=6,BD=3,则BF=( )A .7B .7.5C .8D .8.5 5.若37a b =,则b a a -等于( ) A .34 B .43 C .73 D .376.如图,在同一平面直角坐标系中,反比例函数y =k x与一次函数y =kx ﹣1(k 为常数,且k >0)的图象可能是( )A.B.C.D.7.如图,点D,E分别在△ABC的AB,AC边上,增加下列条件中的一个:①∠AED=∠B,②∠ADE=∠C,③AE DEAB BC=,④AD AEAC AB=,⑤AC2=AD•AE,使△ADE与△ACB一定相似的有()A.①②④B.②④⑤C.①②③④D.①②③⑤8.观察下列每组图形,相似图形是()A.B.C.D.9.已知2x=3y,则下列比例式成立的是()A.B.C.D.10.如图,∠APD=90°,AP=PB=BC=CD,则下列结论成立的是()A.△PAB∽△PCA B.△ABC∽△DBA C.△PAB∽△PDA D.△ABC∽△DCA 11.河堤横断面如图所示,堤高BC=5米,迎水坡AB的坡比1:3,则AC的长是( )A.10米B.53米C.15米D.103米12.如图,是我们数学课本上采用的科学计算器面板,利用该型号计算器计算cos55°,按键顺序正确的是()A.B.C.D.二、填空题13.如图,四边形ABCD与四边形EFGH位似,其位似中心为点O,且43OEEA=,则FGBC=______.14.如图,一条河的两岸有一段是平行的,在河的南岸边每隔5米有一棵树,在北岸边每隔50米有一根电线杆.小丽站在离南岸边15米的P点处看北岸,发现北岸相邻的两根电线杆恰好被南岸的两棵树遮住,并且在这两棵树之间还有三棵树,则河宽为________米.15.如图,在2×2的网格中,以顶点O为圆心,以2个单位长度为半径作圆弧,交图中格线于点A,则tan∠ABO的值为_____.16.如图,直立在点B 处的标杆AB =2.5m ,站立在点F 处的观测者从点E 看到标杆顶A ,树顶C 在同一直线上(点F ,B ,D 也在同一直线上).已知BD =10m,FB =3m,人的高度EF =1.7 m,则树高DC 是________.(精确到0.1 m)17.如图,小巷左右两侧是竖直的墙,一架梯子斜靠在左侧墙上与地面成60°角时,梯子顶端距离地面23米,若保持梯子底端位置不动,将梯子斜靠在右端时,与地面成45°,则小巷的宽度为_____米(结果保留根号).18.已知反比例函数y=2m x-,当x >0时,y 随x 增大而减小,则m 的取值范围是_____. 19.如图所示,将一副三角板摆放在一起,组成四边形ABCD ,∠ABC =∠ACD =90°,∠ADC =60°,∠ACB =45°,连接BD ,则tan ∠CBD 的值为_____.20.如图,若点 A 的坐标为 ()1,3 ,则 sin 1∠ =________.三、解答题21.如图,在ABC V 中,AB AC =,点E 在边BC 上移动(点E 不与点B ,C 重合),满足DEF B ∠=∠,且点D 、F 分别在边AB 、AC 上.(1)求证:BDE CEF △∽△.(2)当点E 移动到BC 的中点时,求证:FE 平分DFC ∠.22.如图,在平面直角坐标系中,△ABC 的三个顶点坐标分别为A(-2,1),B(-1,4),C(-3,2).(1)以原点O 为位似中心,位似比为1∶2,在y 轴的左侧,画出△ABC 放大后的图形△A 1B 1C 1,并直接写出C 1点的坐标;(2)如果点D(a ,b)在线段AB 上,请直接写出经过(1)的变化后点D 的对应点D 1的坐标.23.如图,已知反比例函数11k y x=(k 1>0)与一次函数2221(0)y k x k =+≠相交于A 、B 两点,AC ⊥x 轴于点C . 若△OAC 的面积为1,且tan ∠AOC =2 .(1)求出反比例函数与一次函数的解析式;(2)请直接写出B 点的坐标,并指出当x 为何值时,反比例函数y 1的值大于一次函数y 2的值.24.如图,在正方形ABCD 中,点M 、N 分别在AB 、BC 上,AB=4,AM=1,BN=34.(1)求证:ΔADM ∽ΔBMN ;(2)求∠DMN 的度数.25.如图,锐角三角形ABC 中,CD ,BE 分别是AB ,AC 边上的高,垂足为D ,E .(1)证明:ACD ABE V V ∽.(2)若将D ,E 连接起来,则AED V 与ABC V 能相似吗?说说你的理由.【参考答案】***试卷处理标记,请不要删除一、选择题1.D解析:D【解析】【分析】根据反比例函数的性质及图象上点的坐标特点对各选项进行逐一分析即可.【详解】A 、∵当x =﹣3时,y =2,∴此函数图象过点(﹣3,2),故本选项正确;B 、∵k =﹣6<0,∴此函数图象的两个分支位于第二、四象限,故本选项正确;C 、∵当x =﹣2时,y =3,∴当x <﹣2时,0<y <3,故本选项正确;D 、∵k =﹣6<0,∴在每个象限内,y 随着x 的增大而增大,故本选项错误; 故选:D .【点睛】本题考查的是反比例函数的性质,熟知反比例函数的增减性是解答此题的关键.2.D解析:D【解析】【分析】根据已知及相似三角形的判定定理,找出题中存在的相似三角形即可.【详解】∵∠1=∠2,∠C=∠C,∴△ACE∽△ECD,∵∠2=∠3,∴DE∥AB,∴△BCA∽△ECD,∵△ACE∽△ECD,△BCA∽△ECD,∴△ACE∽△BCA,∵DE∥AB,∴∠AED=∠BAE,∵∠1=∠2,∴△AED∽△BAE,∴共有4对,故此选D 选项.【点睛】本题考查学生对相似三角形判断依据的理解掌握,也考察学生的看图分辨能力.3.B解析:B【解析】【分析】根据相似三角形的判定和性质,可得出这两个三角形相似,相似三角形的周长之比等于相似比,面积之比等于相似比的平方.【详解】解:∵用放大镜看△ABC,若边BC的长度变为原来的2倍,∴放大镜内的三角形与原三角形相似,且相似比为2∴边AB的长度也变为原来的2倍,故A正确;∴∠BAC的度数与原来的角相等,故B错误;∴△ABC的周长变为原来的2倍,故C正确;∴△ABC的面积变为原来的4倍,故D正确;故选B【点睛】本题考查了相似三角形的性质,相似三角形的周长之比等于相似比,面积之比等于相似比的平方.4.B解析:B【解析】【分析】由直线a∥b∥c,根据平行线分线段成比例定理,即可得AC BDCE DF=,又由AC=4,CE=6,BD=3,即可求得DF的长,则可求得答案.【详解】解:∵a∥b∥c,∴AC BD CE DF=,∵AC=4,CE=6,BD=3,∴436DF =,解得:DF=92, ∴937.52BF BD DF =+=+=. 故选B .考点:平行线分线段成比例.5.B解析:B【解析】由比例的基本性质可知a=37b ,因此b a a -=347337b b b -=. 故选B.6.B解析:B【解析】当k >0时,直线从左往右上升,双曲线分别在第一、三象限,故A 、C 选项错误; ∵一次函数y=kx-1与y 轴交于负半轴,∴D 选项错误,B 选项正确,故选B .7.A解析:A【解析】①AED B ∠=∠,且DAE CAB ∠=∠,∴ADE ACB V V ∽,成立.②ADE C ∠=∠且DAE CAB ∠=∠,∴ADE ACB V V ∽,成立. ③AE DE AB BC=,但AED V 比一定与B Ð相等,故ADE V 与ACD V 不一定相似. ④AD AE AC AB=且DAE CAB ∠=∠, ∴ADE ACB V V ∽,成立.⑤由2AC AD AE =⋅,得AC AE AD AC=无法确定出ADE V , 故不能证明:ADE V 与ABC V 相似.故答案为A . 点睛:本题考查了相似三角形的判定定理:(1)两角对应相等的两个三角形相似;(2)两边对应成比例且夹角相等的两个三角形相似;(3)三边对应成比例的两个三角形相似;(4)如果一个直角三角形的斜边和一条直角边与另一个直角三角形的斜边和一条直角边对应成比例,那么这两个直角三角形相似.8.D解析:D【解析】【分析】根据相似图形的定义,形状相同,可得出答案.【详解】解:A、两图形形状不同,故不是相似图形;B、两图形形状不同,故不是相似图形;C、两图形形状不同,故不是相似图形;D、两图形形状相同,故是相似图形;故选:D.【点睛】本题主要考查相似图形的定义,掌握相似图形形状相同是解题的关键.9.C解析:C【解析】【分析】把各个选项依据比例的基本性质,两内项之积等于两外项之积,已知的比例式可以转化为等积式2x=3y,即可判断.【详解】A.变成等积式是:xy=6,故错误;B.变成等积式是:3x+3y=4y,即3x=y,故错误;C.变成等积式是:2x=3y,故正确;D.变成等积式是:5x+5y=3x,即2x+5y=0,故错误.故选C.【点睛】本题考查了判断两个比例式是否能够互化的方法,即转化为等积式,判断是否相同即可.10.B解析:B【解析】【分析】根据相似三角形的判定,采用排除法,逐条分析判断.【详解】∵∠APD=90°,而∠P AB≠∠PCA,∠PBA≠∠P AC,∴无法判定△P AB与△PCA相似,故A错误;同理,无法判定△P AB与△PDA,△ABC与△DCA相似,故C、D错误;∵∠APD=90°,AP=PB=BC=CD,∴AB=P A,AC=P A,AD=P A,BD=2P A,∴=,∴,∴△ABC∽△DBA,故B正确.故选B.【点睛】本题考查了相似三角形的判定.识别两三角形相似,除了要掌握定义外,还要注意正确找出两三角形的对应边、对应角,可根据图形提供的数据计算对应角的度数、对应边的比.本题中把若干线段的长度用同一线段来表示是求线段是否成比例时常用的方法.11.B解析:B【解析】【分析】Rt△ABC中,已知了坡比是坡面的铅直高度BC与水平宽度AC之比,通过解直角三角形即可求出水平宽度AC的长.【详解】Rt△ABC中,BC=5米,tanA=1:3;∴AC=BC÷tanA=53米;故选:B.【点睛】此题主要考查学生对坡度坡角的掌握及三角函数的运用能力.12.C解析:C【解析】【分析】【详解】利用如图所示的计算器计算2cos55°,按键顺序正确的是.故答案选C.二、填空题13.【解析】【分析】利用位似图形的性质结合位似比等于相似比得出答案【详解】四边形ABCD与四边形EFGH位似其位似中心为点O且则故答案为:【点睛】本题考查了位似的性质熟练掌握位似的性质是解题的关键解析:4 7【解析】【分析】利用位似图形的性质结合位似比等于相似比得出答案.【详解】Q四边形ABCD与四边形EFGH位似,其位似中心为点O,且OE4 EA3=,OE4 OA7∴=,则FG OE4 BC OA7==,故答案为:47.【点睛】本题考查了位似的性质,熟练掌握位似的性质是解题的关键.14.5【解析】根据题意画出图形构造出△PCD∽△PAB利用相似三角形的性质解题解:过P作PF⊥AB交CD于E交AB于F如图所示设河宽为x米∵AB∥CD∴∠PDC =∠PBF∠PCD=∠PAB∴△PDC∽△解析:5【解析】根据题意画出图形,构造出△PCD∽△PAB,利用相似三角形的性质解题.解:过P作PF⊥AB,交CD于E,交AB于F,如图所示设河宽为x米.∵AB∥CD,∴∠PDC=∠PBF,∠PCD=∠PAB,∴△PDC∽△PBA,∴AB PF CD PE=,∴AB15x CD15+=,依题意CD=20米,AB=50米,∴15205015x=+,解得:x=22.5(米).答:河的宽度为22.5米.15.2+3【解析】【分析】连接OA过点A作AC⊥OB于点C由题意知AC=1OA=OB=2从而得出OC=OA2-AC2=3BC=OB﹣OC=2﹣3在Rt△ABC中根据tan ∠ABO=ACBC 可得答案【详解解析:2+.【解析】【分析】连接OA ,过点A 作AC⊥OB 于点C ,由题意知AC=1、OA=OB=2,从而得出OC==、BC=OB ﹣OC=2﹣,在Rt△ABC 中,根据tan∠ABO=可得答案. 【详解】如图,连接OA ,过点A 作AC⊥OB 于点C ,则AC=1,OA=OB=2,∵在Rt△AOC 中,OC==, ∴BC=OB﹣OC=2﹣,∴在Rt△ABC 中,tan∠ABO==2+. 故答案是:2+.【点睛】 本题考查了解直角三角形,根据题意构建一个以∠ABO 为内角的直角三角形是解题的关键.16.2m 【解析】【详解】解:过点E 作EM⊥CD 交AB 与点N∴故答案为52m 【点睛】本题是考查相似三角形的判定和性质关键是做出辅助线构造相似三角形利用相似三角形的性质得出结论即可这类题型可以作垂直也可以作解析:2m【解析】【详解】解:过点E 作EM ⊥CD,交AB 与点N.∴,EN AN EAN ECM EM CMV V ~∴= 30.82.5, 1.7,0.8,10,313AB m EF m AN m BD m FB m CM ==∴===∴=Q Q ,()3.47CM m ∴≈ ()1.7 3.47 5.2.CD m ∴=+≈故答案为5.2m .本题是考查相似三角形的判定和性质.关键是做出辅助线,构造相似三角形,利用相似三角形的性质得出结论即可.这类题型可以作垂直也可以作平行线,构造相似三角形.17.【解析】【分析】本题需要分段求出巷子被分成的两部分再加起来即可先在直角三角形ABC中用正切和正弦分别求出BC和AC(即梯子的长度)然后再在直角三角形DCE中用∠DCE的余弦求出DC然后把BC和DC加解析:222【解析】【分析】本题需要分段求出巷子被分成的两部分,再加起来即可.先在直角三角形ABC中,用正切和正弦,分别求出BC和AC(即梯子的长度),然后再在直角三角形DCE中,用∠DCE 的余弦求出DC,然后把BC和DC加起来即为巷子的宽度.【详解】解:如图所示:3米,∠ACB=60°,∠DCE=45°,AC=CE.则在直角三角形ABC中,ABBC=tan∠ACB=tan60°3AB AC =sin∠ACB=sin60°3∴BC3233=2,AC3233=4,∴直角三角形DCE中,CE=AC=4,∴CDCE=cos45°=22,∴CD=CE×22=4×22=2,∴BD=2,故答案为:2本题需要综合应用正切、正弦.余弦来求解,注意梯子长度不变,属于中档题.18.m>2【解析】分析:根据反比例函数y=当x>0时y随x增大而减小可得出m﹣2>0解之即可得出m的取值范围详解:∵反比例函数y=当x>0时y随x 增大而减小∴m﹣2>0解得:m>2故答案为m>2点睛:本解析:m>2.【解析】分析:根据反比例函数y=2mx-,当x>0时,y随x增大而减小,可得出m﹣2>0,解之即可得出m的取值范围.详解:∵反比例函数y=2mx-,当x>0时,y随x增大而减小,∴m﹣2>0,解得:m>2.故答案为m>2.点睛:本题考查了反比例函数的性质,根据反比例函数的性质找出m﹣2>0是解题的关键.19.【解析】【分析】如图所示连接BD过点D作DE垂直于BC的延长线于点E 构造直角三角形将∠CBD置于直角三角形中设CE为x根据特殊直角三角形分别求得线段CDACBC从而按正切函数的定义可解【详解】解:如解析:31 2 -【解析】【分析】如图所示,连接BD,过点D作DE垂直于BC的延长线于点E,构造直角三角形,将∠CBD置于直角三角形中,设CE为x,根据特殊直角三角形分别求得线段CD、AC、BC,从而按正切函数的定义可解.【详解】解:如图所示,连接BD,过点D作DE垂直于BC的延长线于点E,∵在Rt△ABC中,∠ACB=45°,在Rt△ACD中,∠ACD=90°∴∠DCE=45°,∵DE⊥CE∴∠CEB=90°,∠CDE=45°∴设DE=CE=x,则CD=2x,在Rt△ACD中,∵∠CAD=30°,∴tan∠CAD=33=CDAC,则AC=6x,在Rt△ABC中,∠BAC=∠BCA=45°∴BC=3x,∴在Rt△BED中,tan∠CBD=DEBE=(13)x+=312-故答案为:31 2-.【点睛】本题考查了用定义求三角函数,同时考查了特殊角的三角函数值,如何作辅助线,是解题的关键.20.【解析】【分析】根据勾股定理可得OA的长根据正弦是对边比斜边可得答案【详解】如图由勾股定理得:OA==2sin∠1=故答案为解析:3【解析】【分析】根据勾股定理,可得OA的长,根据正弦是对边比斜边,可得答案.【详解】如图,由勾股定理,得:OA=22OB AB+=2.sin∠1=32ABOA=,故答案为32.三、解答题21.见解析【解析】试题分析:(1)由三角形内角和定理可得:∠BDE=180°-∠B-∠DEB,∠CEF=180°-∠DEF-∠DEB,结合∠B=∠DEF ,可得∠BDE=∠CEF ;由AB=AC 可得∠B=∠C ,由此即可证得:△BDE ∽△CEF ;(2)由(1)中结论:△BDE ∽△CEF 可得:BE DE CF EF=,结合BE=EC 可得:CE DE CF EF=,再结合∠C=∠B=∠DEF ,证得:△DEF ∽△ECF ,由此可得∠DFE=∠EFC ,从而得到结论EF 平分∠DFC.试题解析:(1)∵AB AC =,∴B C ∠=∠,∵180BDE B DAB ∠=︒-∠-∠,180CEF DEF DEB ∠=︒-∠-∠,∵DEF B ∠=∠,∴BDE CEF ∠=∠,BDE CEF V V ∽.(2)∵BDE CEF V V ∽,∴BE DE CF EF=, ∵E 是BC 中点,BE CE =,∴CE DE CF EF=, ∵DEF B C ∠=∠=∠,∴DEF ECF V V ∽,∴DFE CFE ∠=∠,∴EF 平分DFC ∠.22.(1)图见解析,C 1(-6,4);(2)D 1(2a ,2b).【解析】【分析】(1)连接OB 并延长,使BB 1=OB ,连接OA 并延长,使AA 1=OA ,连接OC 并延长,使CC 1=OC ,确定出△A 1B 1C 1,并求出C 1点坐标即可;(2)根据A 与A 1坐标,B 与B 1坐标,以及C 与C 1坐标的关系,确定出变化后点D 的对应点D 1坐标即可.【详解】(1)根据题意画出图形,如图所示:则点C 1的坐标为(-6,4);(2)变化后D 的对应点D 1的坐标为:(2a ,2b ).【点睛】运用了作图-位似变换,画位似图形的一般步骤为:①确定位似中心,②分别连接并延长位似中心和能代表原图的关键点;③根据相似比,确定能代表所作的位似图形的关键点;顺次连接上述各点,得到放大或缩小的图形.23.(1)12y x =;21y x =+;(2)B 点的坐标为(-2,-1);当0<x <1和x <-2时,y 1>y 2.【解析】【分析】(1)根据tan ∠AOC =AC OC=2,△OAC 的面积为1,确定点A 的坐标,把点A 的坐标分别代入两个解析式即可求解;(2)根据两个解析式求得交点B 的坐标,观察图象,得到当x 为何值时,反比例函数y 1的值大于一次函数y 2的值.【详解】解:(1)在Rt △OAC 中,设OC =m .∵tan ∠AOC =AC OC =2,∴AC =2×OC =2m . ∵S △OAC =12×OC×AC =12×m×2m =1,∴m 2=1.∴m =1(负值舍去). ∴A 点的坐标为(1,2).把A 点的坐标代入11k y x=中,得k 1=2. ∴反比例函数的表达式为12y x =. 把A 点的坐标代入221y k x =+中,得k 2+1=2,∴k 2=1.∴一次函数的表达式21y x =+.(2)B 点的坐标为(-2,-1).当0<x <1和x <-2时,y 1>y 2.【点睛】本题考查反比例及一次函数的的应用;待定系数法求解析式;图象的交点等,掌握反比例及一次函数的性质是本题的解题关键.24.(1)见解析;(2)90°【解析】【分析】(1)根据43AD MB =,43AM BN =,即可推出AD AM MB BN=,再加上∠A=∠B=90°,就可以得出△ADM ∽△BMN ; (2)由△ADM ∽△BMN 就可以得出∠ADM=∠BMN ,又∠ADM+∠AMD=90°,就可以得出∠AMD+∠BMN=90°,从而得出∠DMN 的度数.【详解】(1)∵AD=4,AM=1∴MB=AB-AM=4-1=3 ∵43AD MB =,14334AM BN == ∴AD AM MB BN= 又∵∠A=∠B=90°∴ΔADM ∽ΔBMN(2)∵ΔADM ∽ΔBMN∴∠ADM=∠BMN∴∠ADM+∠AMD=90°∴∠AMD+∠BMN=90°∴∠DMN=180°-∠BMN-∠AMD=90°【点睛】本题考查了正方形的性质的运用,相似三角形的判定及性质的运用,解答时证明△ADM ∽△BMN 是解答的关键.25.(1)见解析;(2)能,理由见解析.【解析】【分析】(1)根据已知利用有两个角相等的三角形相似判定即可;(2)根据第一问可得到AD :AE=AC :AB ,有一组公共角∠A ,则可根据两组对应边的比相等且相应的夹角相等的两个三角形相似进行判定.【详解】()1证明:ACD ABE V V ∽.证明:∵CD ,BE 分别是AB ,AC 边上的高,∴90ADC AEB ∠=∠=o .∵A A ∠=∠,∴ACD ABE V V ∽.()2若将D ,E 连接起来,则AED V 与ABC V 能相似吗?说说你的理由. ∵ACD ABE V V ∽,∴::AD AE AC AB =.∴AD:AC=AE:AB∵A A ∠=∠,∴AED ABC V V ∽.【点睛】考查相似三角形的判定与性质,掌握相似三角形的判定定理是解题的关键.。
2020-2021济南外国语学校华山校区小学三年级数学上期中试卷及答案一、选择题1.不能验算739+164=903的算式是()。
A. 739-164B. 903-164C. 903-7392.计算234+99时,正确的方法是()。
A. 234+100+1B. 234-100-1C. 234+100-13.水果店第一次运来水果1吨,第二次又运来水果2000千克,两次共运来水果()。
A. 2001千克B. 3吨C. 12吨D. 1200千克4.一只大象约重7()。
A. 千克B. 吨C. 克5.把4吨萝卜分4次运往青岛,平均每次运()千克。
A. 100B. 1C. 10006.小明为贫困山区捐款137元,小华捐款158元,估计一下他们一共捐款大约是()元。
A. 200B. 300C. 400D. 500 7.700+900=()A. 1500B. 1400C. 1600D. 1800 8.586+234,下面说法正确的是()A. 它们的和比900大一些B. 它们的和比800小一些C. 586不到600,234比300小些,它们的和肯定在800和900之间D. 上面的说法都不对9.1秒可以()A. 读一篇文章B. 眨(zhǎ)一次眼C. 吃一顿饭D. 跑100米10.一台电风扇原来卖539元,现在卖480元。
这台电风扇价格现在比原来便宜()元钱。
A. 131B. 149C. 5911.三位同学百米赛跑时间是:小明10分15秒,小亮10分56秒,小丁10分9秒,谁跑得最快?()A. 小明B. 小亮C. 小丁12.100米赛跑,小华用了20秒,小敏用了19秒,小军用了17秒。
三个人中,()的速度最慢。
A. 小华B. 小敏C. 小军二、填空题13.用3,4,5三个数字组成的最大三位数与最小三位数相差________。
14.把49+33,22+81,109+28,209-108,540+270,690-540这些算式按得数从大到小排列。
济南外国语学校华山校区八年级上册期中生物期中试卷(含答案)一、选择题1.下列属于腔肠动物和扁形动物共同特征的是()A.生活在水中B.体壁由两个胚层构成C.身体背腹扁平D.有口无肛门2.下列关于蚯蚓的叙述,错误的是()A.属于环节动物B.是优良的蛋白质饲料C.能处理有机废物,提高土壤肥力D.体表有外骨骼3.下列动物都属于腔肠动物的是()A.绦虫和海葵B.海蜇和珊瑚虫C.丝虫和沙蚕D.水螅和蚊4.下列对动物类群主要特征的描述,错误的是A.腔肠动物:身体呈辐射对称;体表有刺细胞;有口无肛门B.鱼:生活在水中,体表常有鳞片覆盖;用鳃呼吸,通过尾部和躯干部的摆动以及鳍的协调作用游泳C.软体动物:柔软的身体表面有外套膜;大多具有贝壳;运动器官是足D.扁形动物:身体呈两侧对称;背腹扁平;有口有肛门5.如图是鸟的呼吸系统、骨骼、肌肉示意图,下列描述错误..的是()A.鸟类气体交换的器官是甲图的②和③B.乙图中的④上高耸的突起叫做龙骨突C.丙图的⑤附着在乙图的④上,可以牵动两翼D.甲、乙、丙的结构特点都与鸟类飞行相适应6.结构与功能相适应是生物学观点之一,下列能说明该观点的是()A.鼻腔内毛细血管丰富,适于清洁空气B.肺泡壁和毛细血管壁都很薄,利于气体交换C.鸟的长骨中空,利于提供能量进行飞行D.根尖分生区细胞小,利于吸收水和无机盐7.下表所列的“几类动物的一些主要特征”中,错误的一项是()选项A B C D类群腔肠动物线形动物节肢动物爬行动物主要特征身体呈辐射对称身体柔软体表有外骨骼在陆地上产卵A.A B.B C.C D.D8.体温恒定有利于动物的区域分布、生存和繁衍,下列动物中体温恒定的一组是()A.梅花鹿和蚯蚓B.麻雀和海豹C.麻雀和螳螂D.家鸽和蜥蜴9.图是长骨的结构图,下列叙述正确的是()A.②是骨膜,与骨头的长长有关B.⑦是骨质,包括⑥骨松质和⑤骨密质C.④内骨髓终生都是红色D.③属于结缔组织10.在公共汽车上,年轻人应主动给老年人让座,这是关爱老人的一种美德。
2020届济南外国语学校高三英语期中考试试卷及参考答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AExciting Adventure Options to Choose From!BIRD WALK(Any time of year)-Join us for a private bird walk through our sanctuary(保护区)。
The Bent's grasslands, trees and woods provide great habitat(栖息地)for birds moving from one place to another, such as Warblers, Vireos, Indigo Buntings, Thrushes, Orioles, and more. This walk will be made to the members in your party.Suitable for ages 5 and upProgram Fee:$150NATURE HIKE(Any time of year)-Take a private hike with Bent of the River! Your personal guide will show you notable habitats and wildlife around the center trails. Nature is exciting and always changing, so you never know what we will find along the way! This program is ideal for people who want to enjoy beautiful scenery while hiking.Suitable for ages 8 and upProgram Fee:$150POMPERAUG RIVER EXPLORATION(June and July only)-Many fascinating creatures live in and around the Pomperaug River! During this recreational(休闲的)program, an Audubon naturalist will share the human and natural history of the river and teach you how to catch fish and animals. The Bent will supply you with necessary tools, such as nets, containers, and field guides. Once the animals are caught, we will observe and identify(确定身份)them and learn how they can help show the health of the river before we put them back to the wild.Suitable for ages 8 and upProgram Fee:$150OWL PROWL(January and February only)-Enjoy a special guided adventure in search of one of the most beloved groups of birds-owls(猫头鹰)!We will be prowling for owls on awalk through the grassland and forests in hopes of seeing one of the three owl species known to live in Connecticut: the Great-horned Owl, Barred Owl, or Eastern Screech-Owl.Evening eventSuitable for ages 10 and upProgram Fee:$2251.Which of the programs is suitable for the Browns with a girl of five years old?A.BIRD WALK.B.NATURE HIKE.C.POMPERAUG RIVER EXPLORATION.D.OWL PROWL.2.What will you do with the fish you catch in POMPERAUG RIVER EXPLORATION?A.Find out their health.B.Do a scientific research.C.Cook them as food on the table.D.Set them free back to the river.3.Whom is this text written for?A.Students.B.Teachers.C.Scientists.D.Adventurers.BHundreds of millions of people watched on television on July 20, 1969, when American astronauts Neil Armstrong and Buzz Aldrin became the first humans to land on the moon. Back then, businesses sold many products connected to the event and many such products are now on sales again — in celebration of the moon landing’s 50th anniversary.A limited number of Omega’s gold Speedmaster watches — the same kind that Buzz Aldrin wore on the moon — will be sold at $34,600. Omega Speedmaster watches have been an important part of space travel since NASA chose them for its moon landing in 1965. Other watches had failed required tests. Omega gave its gold Speedmasters to the astronauts at a dinner in 1969 before the landing. Another less costly type of silver Speedmasters will be sold at $ 9,650. It carries a picture of Aldrin stepping down from the moon lander.Something for children-as well as adults — is the NASA Apollo 11 moon lander set. Made by Lego, it is a group of small pieces to put together to make a model of the moon lander.Other things for sale include the anti-gravity Fisher Space Pens,developed just for the Apollo 11 mission. They work even when writing upside down. Now Fisher Space Pen Company has a limited-edition pen for sale at anout-of this-worldprice: $700, with real material from the Apollo 11 spacecraft.Back in 1969, companies were quick to show their Apollo 11 connections with media and advertisements. The food company Stouffer’s made sure consumers knew it provided food for Apollo 11 astronauts once they returned to Earth. It started the ad campaign “Everybody who’s been to the moon is eating Stouffer’s”. Fifty years later, the company is celebrating with a media campaign to share some recipes from 1969.Marketing experts David Meerman Scott says, “Since 1972,we’ve gone around and around the earth manytimes, and it is not interesting to people any more. I’m not sure whether they can accept such crazy prices. Now NASA has had plans to go to Mars in the 2030s and marketing efforts for a NASA Mars mission should be in development.”4. What can we learn about the gold Speedmaster watch?A. It will be sold at $34,600.B. NASA bought itats9,650.C. It has Aldrin’s picture inside.D. It was chosen by NASA in 1969.5. What does the underlined word “out-of-this-world” in paragraph 4 mean?A. Extremely fair.B. Surprisingly high.C. Really low.D. Truly worthwhile.6. What does David Meerman Scott mean?A. It is a waste of money to go around and around the moon.B. People will be interested in the products connected to Apollo.C. Since 1972,governments have lost interest in moon explorations.D. The event of going to Mars will be another good chance to advertise.7. What is the author’s main purpose in writing the text?A. To show how to design the best advertisement.B. To forecast the sales of the products in the text.C. To introduce some of the products connected to Apollo 11.D. To celebrate the 50th anniversary of the first moon landing.CWhile the start of a new school year is always exciting, this year was even more so for some elementary school students inAuckland,New Zealand. They became the world’s first kids to be “taught” by a digital teacher.Before you start imagining a human-like robot walking around the classroom, Will is just an avatar that appears on the student’s desktop, or smartphone screen, when ordered to come.The autonomous animation platform has been modeled after the human brain and nervous system, allowing it to show human-like behavior. The digital teacher is assigned to teach Vector’s “Be sustainable with energy”— a free program forAucklandelementary schools.Just like the humans it replaced, Will is able to instantly react to the students’ responses to the topic. Thanks to a webcam and microphone, the avatar not only responds to questions the kids may have, but also picks up non-verbal cues. For instance, if a student smiles at Will, he responds by smiling back. This two-way interactionnot only helps attract the students’ attention, but also allows the program’s developers to monitor their engagement, and make changes if needed.Nikhil Ravishankar believes that Will-like avatars could be a novel way to catch the attention of the next generation. He says, “I have a lot of hope in this technology as a means to deliver cost-effective, rich, educational experience in the future.”The program, in place since August 2018, has been a great success thus far. Ravishankar says, “ What was fascinating to me was the reaction of the children to Will. The way they look at the world is so creative and different, and Will really captured their attention.” However, regardless of how popular it becomes, Will is unlikely to replace human educators any time soon.8. What was special for some elementary school students inAuckland?A. A digital teacher taught them.B. They first saw something digital.C. This was the start of a new school year.D. They could get close to smartphone screen.9. What is the benefit of this two-way interaction?A. It can smile back.B. It can use microphone.C. It can talk any topic for free.D. It can change if necessary.10. What’s Ravishankar’s attitude to Will’s replacing Human educators soon?A. Optimistic.B. Doubtful.C. Unclear.D. Disapproving.11. What might be the best title for the passage?A. New High-tech Contributes to EducationB. The World’s First Digital Teacher Appears in Classroom.C. The World’s First Digital Teacher, a Help to StudentsD.New ZealandWill Replace Teachers in ClassroomsDYou’re in a crowd of people who are all asking for the same thing. How do you make your voice heard above the rest? Be different. Don’t shout. Lisa, 25, was waiting to board a plane flying fromLondontoAustriafor Christmaswhen the flight was cancelled.“There were about a hundred of us unable to leave,” she says. “Everyone else was shouting at the airportstaff. Instead of joining in, I walked up to the man behind the ticket desk very quietly and said, ‘This must be so awful for you! I don’t know how you deal with these situations—it’s not even your fault. I could never handle it as well as you are.’ Without my even asking, he found me a seat on another airline with an upgrade to first class. He was happy to do a favor forsomeone who was appreciative instead of unfriendliness.”Flattery (恭维) is an essential element of the sweet-talk strategy. “It’s human psychology that stroking a person’s ego (自我) with a few well-directed praises makes them want to prove you right,” says apsychologist. “Tell someone they’re pretty and they’ll instantly fix their hair; praise their sense of humor and they’ll tell a joke.”You need help and there’s ly no reason that the person will want to lend a hand. Allison, 26. a lawyer, realized she’d made a huge mistake on a batch of documents. “The only way I could fix the problem was to get the help of a colleague who I knew didn’t like me,” she said.Allison then went to the woman’s office and explained her problem. “As I was saying to the boss the other day you’re the only person who would know how to handle a situation like this, what would you suggest I do?” “Feeling pumped up (鼓励), she set about helping me and we finished the job on time, and she was happy to help.” Allison said.12. Whatwould have happened at the airport according to paragraph 1?A. The departure hall was filled with noise.B. Someone screamed just lo be different.C. The passengers waited on board patiently.D. The airport stuff were rude to the passengers.13. Why did the man put Lisa on another airline?A. He admired Lisa’s beauty.B. He appreciated her attitude.C. He was ready to help others.D. He was blamed for the cancellation.14. What is the third paragraph mainly about?A. The potential benefits of ego.B. The strategy to start small talk.C. The great importance of flattery.D. The value of humor in daily life.15. What can we learn about Allison’s colleague?A. She was a popular lawyer.B. She was always ready to help others.C. She always got praise from Allison.D. She did a great favor for Allison eventually.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
2020届济南市外国语学校高三英语期中试题及答案解析第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AOvernight French ToastWhat You’ll Need•16-ounce loaf of French bread•5 eggs•1 1 /2 cups milk•1/2 cup half-and-half•1/3 cup maple syrup(枫糖浆)•1/2 teaspoon salt•foil(锡箔纸)•2 tablespoons melted butter(for topping)•2 tablespoons maple syrup(for topping)What to Do•With an adult’s help, cut the bread into 1-inch slices.•Place the eggs, milk, half-and-half, maple syrup, and salt into a large bowl. Stir(揽拌)the mixture until blended(混合均匀).•Place the sliced bread into a baking dish. Pour the mixtureover the bread and press the slices into it. Cover the dish with foil and refrigerate overnight.•Remove the dish from the refrigerator at least one hour before baking. Ask an adult for help to preheat the oven to 375°F. Bake the French toast for 35 minutes or until golden brown.•For the topping, combine the melted butter and 2 tablespoons of maple syrup. Pour it over the French toast before serving.1.How much salt will you need to make a French toast?A.1/3 cup.B.1/2 teaspoon.C.2 tablespoons.D.16 ounces.2.How will you use foil?A.Place the sliced breadB.Cover the dish.C.Remove the dish.D.Eat the French toast.3.Who is the passage written for?A.Teachers.B.Parents.C.Cooks.D.Kids.BI don’t want to talk about being a woman scientistagain. There was a time in my life when people asked constantly for stories about what it’s like to work in a field dominated (controlled) by men. I was never very good at telling those stories because truthfully I never found them interesting. What I do find interesting is the origin of the universe, the shape of space, time and the nature of black holes.At 19, when I began studying astrophysics (天体物理学), it did not bother me in the least to be the only woman in the classroom. But while earning my Ph.D. at MIT and then as a post-doctor doing space research, the issue started to bother me. My every achievement — jobs, research papers, awards — was viewed through the lens (镜片) of gender (性别) politics. So were my failures. Sometimes, when I was pushed into an argument on left brain versus (相对于) right brain, or nature versus nurture (培育), I would instantly fight fiercely on my behalf and all womankind.Then one day a few years ago, out of my mouth came a sentence that would eventually become my reply to any and all provocations (挑衅): I don’t talk about that anymore. It took me 10 years to get back the confidence I had at 19 and to realize that I didn’t want to deal with gender issues. Why should curing sexism be yet another terrible burden on every female scientist? After all, I don’t study sociology or political theory.Today I research and teach at Barnard, a women’s college in New York City. Recently, someone asked me how many of the 45 students in my class were women. You cannot imagine my satisfaction at being able to answer, 45.I know some of my students worry how they will manage their scientific research and a desire for children. And I don’t dismiss those concerns. Still, I don’t tell them “war” stories. Instead, I have given them this: the visual of their physics professor heavily pregnant doing physics experiments. And in turn they have given me the image of 45 women driven by a love of science. And that’s a sight worth talking about.4. Why doesn’t the author want to talk about being a woman scientist again?A. She is fed up with the issue of gender discrimination (歧视).B. She feels unhappy working in male-dominated fields.C. She is not good at telling stories of the kind.D. She finds space research more important.5. From Paragraph 2, we can infer that people would attribute (把……归因于) the author’s failures to ________.A. the burden she bears in a male-dominated societyB. her involvement in gender politicsC. her over-confidence as a female astrophysicistD. the very fact that she is a woman6. What did the author constantly fight against while doing her Ph.D. and post-doctoral research?A. Lack of confidence in succeeding in space science.B. Unfair accusations from both inside and outside her circle.C. People’s fixed attitude toward female scientists.D. Widespread misconceptions about nature and nurtured.7. What does the image the author presents to her students suggest?A. Women students needn’t have the concerns of her generation.B. Women can balance a career in science and having a family.C. Women have more barriers on their way to academic success.D. Women now have fewer problems pursuing a science career.CIt is essential that students have a category of school-related activities they can participate in. These activities can range from activities during normal school hours to after-school activities. No matter the time, these activities should be available to every student, and at Victory Pioneers International Schools (V.P.I.S) it is encouraged that every student participate in at least one activity, educational and recreational.One of the primary reasons school activities are important at V.P.I.S. is because it gives students the exercise they might not normally receive. Most popularly, these types of activities include major sports such as football, basketball, baseball, tennis, track and field and soccer but also might include gymnasium games and other games.Activities during V.P.I.S. also make a good impression on colleges if students are planning to pursue more education. Colleges look for students who do not just go to school and go home after school. These activities range from participating in clubs and sports to volunteering after school at a recreation center or having a part-time job. If a college sees you maintained good grades while participating in these activities, it will be impressed.V.P.I.S. activities also allow students to be creative. Gifted-and-talented activities allow gifted students to participate in what they otherwise would never have experienced in the classroom. They are a great way to allow students to be creative. Additionally, participating in clubs such as drama that appeal to students’ interest alsoallows them to expand their knowledge and be creative.Students also can have their interests expanded by participating in activities. These activities could consist of anything, such as joining the Future Business Leaders, the school’s debate team and the chess team, to name a few. By participating in these activities, a student might realize he is interested in something he never knew he was interested in before.8. What can we learn about activities at V.P.I.S.?A. Not every student has access to them.B. Students are required to take part in them after school.C. They give students exercise that might not be got in other schools.D. Educational activities are more popular with the students.9. What benefits can the students get from the activities?A. They can get extra grades when applying for colleges.B. They will become more gifted and talented .C. They may expand their knowledge in drama.D. They may better know their own interests.10. Which of the following is a suitable title for the passage?A. The Benefits of V.P.I.S. ActivitiesB. School-related Activities at V.P.I.S.C. Colleges Need Creative StudentsD. Activities Make You Creative11. Where is the passage probably from?A. A scientific magazine.B. A college application guideline.C. A club introduction.D. The website of V.P.I.S.DA North Atlantic right whale calf(幼崽) was discovered dead on the beach of an island off North Carolina. The male newborn was found on North Core Banks, part of the Cape Lookout National Seashore. The reports indicate that the animal died during birth or shortly after, according to the National Oceanic and Atmospheric Administration(NOAA). Scientists took DNA to determine the calf’s mother.This is the beginning of the right whale’s reproduction(繁殖) season, which begins mid-November and runs through mid-April. NOAA called this death a disastrous start to the season. Each new right whale calf brings so much hope for this badly endangered animals, and losses like this have a great impact on their recovery, NOAA said.The right whale is one of the rarest marine mammals(哺乳动物) in the world, according to NOAA. They will soon be extinct unless something is done to save it, researchers warn. This kind of whale has been experiencing an Unusual Death Event over the past three years, according to NOAA. Since 2017, at least 32 dead and 13 seriously wounded whales have been documented by the organization. “This means more than 10 percent of the remaining population,” according to NOAA.NOAA posted a piece of news on Monday, the same day they announced the calf’s death, warning boaters to be watchful as the whales are migrating(迁徙) nearly 1,000 miles along the Atlantic Coast. The organization calls for boaters to be watchful, slow down and to give these endangered whales plenty of room. They also ask all fishermen to remove their unused nets from the ocean to help avoid possibledamage.12. Why did scientists take DNA of the calf?A. To save its mother.B. To confirm its identity.C. To determine the time of its death.D. To uncover the cause of its death.13. How many right whales are left according to the passage?A. About 40.B. About 50.C. About 400.D. About 500.14. What do we know aboutNorth Atlanticright whales?A. Their reproduction season usually last about half a year.B. They are the rarest marine mammals in the world.C. They are experiencing a high death rate of newborns.D. Their habitat runs nearly 1,000 miles along the coast.15. What’s the main purpose of the news posted on Monday?A. To announce the calf’s unusual death.B. To remind boaters to watch the whales.C. To protect the boats against the whales.D. To assist the whales’ seasonal migration.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
2020-2021济南外国语学校华山校区小学五年级数学上期中试卷及答案一、选择题1.下面的数中,()最接近1.76。
A. B. C.2.乘积最大的算式是()。
A. 3.45×2.36B. 0.345×236C. 34.5×23.63.计算2.2÷0.7的商是3,余数是1。
()A. 正确B. 错误4.得数为5.1的算式是()。
A. 0.51×10B. 5.1×0.1C. 5.1÷105.三角形三个顶点的位置用数对表示如下:A(2,6),B(5,2),C(2,2),则三角形ABC是()。
A. 锐角三角形B. 直角三角形C. 钝角三角形D. 无法判断6.点A的位置是(5,7),点B的位置是(6,9),点C与A在同一列,点C与B在同一行,那么点C的位置是()A. (5,9)B. (6,7)C. (5,6)7.如图,如果将三角形ABC向左平移2格得到三角形A′B′C′ ,则新图形中点A′(点A平移后对应的点)的位置用数对表示为( )。
A. (5,1)B. (1,1)C. (7,1)D. (3,3) 8.如果用(x,4 )表示小强在教室里的座位,那么下面说法错误的是()。
A. 小强的座位一定在第4列B. 小强的座位一定在第4行C. 小强的座位可能在第4列9.对于方程5.4x-0.4 x =2.8得到5 x =2.8,运用的是()。
A. 乘法交换律B. 乘法分配律C. 乘法结合律10.用乘法分配律计算3.7×9.9,下面第()种算法是正确的。
A. 3.7×10-0.1B. 3.7×9+0.9C. 3.7×10-3.7D. 3.7×10-0.37 11.下面表示“1.2×0.7”的意义,错误的图是()。
A. B.C. D.12.乐乐冲洗15张照片,每张照片的冲洗费是0.85元,乐乐笔算如下,箭头所指的“85”表示()。
2020-2021济南外国语学校华山校区八年级数学上期中试卷及答案一、选择题1.“五一”期间,某中学数学兴趣小组的同学们租一辆小型巴士前去某地进行社会实践活动,租车租价为180元.出发时又增加了两位同学,结果每位同学比原来少分摊了3元车费.若小组原有x 人,则所列方程为( )A .18018032x x -=-B .18018032x x -=+C .18018032x x-=+ D .18018032x x -=- 2.已知一个正多边形的内角是140°,则这个正多边形的边数是( ) A .9B .8C .7D .6 3.如图,在△ABC 和△CDE 中,若∠ACB=∠CED=90°,AB =CD ,BC =DE ,则下列结论中不正确的是( )A .△ABC≌△CDEB .CE =AC C .AB⊥CD D .E 为BC 的中点4.如图,直线AB ∥CD ,∠C =44°,∠E 为直角,则∠1等于( )A .132°B .134°C .136°D .138°5.如图,在ABC ∆中,90A ∠=o ,30C ∠=o ,AD BC ⊥于D ,BE 是ABC ∠的平分线,且交AD 于P ,如果2AP =,则AC 的长为( )A .2B .4C .6D .86.如图,直线123l l l 、、表示三条相互交叉的公路,现要建一个货物中转站,要求它到三条公路的距离相等,则可供选择的地址有( )A .一处B .二处C .三处D .四处7.如图,ABC △是一块直角三角板,90,30C A ∠=︒∠=︒,现将三角板叠放在一把直尺上,AC 与直尺的两边分别交于点D ,E ,AB 与直尺的两边分别交于点F ,G ,若∠1=40°,则∠2的度数为( )A .40ºB .50ºC .60ºD .70º8.如果(x +1)(2x +m )的乘积中不含x 的一次项,则m 的值为( )A .2B .-2C .0.5D .-0.59.小淇用大小不同的 9 个长方形拼成一个大的长方形 ABCD ,则图中阴影部分的面积是( )A .(a + 1)(b + 3)B .(a + 3)(b + 1)C .(a + 1)(b + 4)D .(a + 4)(b + 1) 10.某服装加工厂计划加工400套运动服,在加工完160套后,采用了新技术,工作效率比原计划提高了20%,结果共有了18天完成全部任务.设原计划每天加工x 套运动服,根据题意可列方程为A .()16040018x 120%x++= B .()16040016018x 120%x -++= C .16040016018x 20%x -+= D .()40040016018x 120%x-++= 11.如图,把一张矩形纸片ABCD 沿EF 折叠后,点A 落在CD 边上的点A′处,点B 落在点B′处,若∠2=40°,则图中∠1的度数为( )A .115°B .120°C .130°D .140°12.如图,已知在△ABC,AB =AC .若以点B 为圆心,BC 长为半径画弧,交腰AC 于点E ,则下列结论一定正确的是( )A .AE =ECB .AE =BEC .∠EBC =∠BACD .∠EBC =∠ABE二、填空题13.如图是两块完全一样的含30°角的直角三角尺,分别记做△ABC 与△A′B′C′,现将两块三角尺重叠在一起,设较长直角边的中点为M ,绕中点M 转动上面的三角尺ABC ,使其直角顶点C 恰好落在三角尺A′B′C′的斜边A′B′上.当∠A =30°,AC =10时,两直角顶点C ,C′间的距离是_____.14.已知射线OM.以O 为圆心,任意长为半径画弧,与射线OM 交于点A ,再以点A 为圆心,AO 长为半径画弧,两弧交于点B ,画射线OB ,如图所示,则∠AOB=________(度)15.在代数式11,,52x x x +中,分式有_________________个. 16.已知关于x 的分式方程233x k x x -=--有一个正数解,则k 的取值范围为________. 17.清明节期间,初二某班同学租一辆面包车前去故宫游览,面包车的租金为600元,出发时又增加了5名同学,且租金不变,这样每个同学比原来少分摊了10元车费,若设实际参加游览的同学,一共有x 人则可列分式方程________.18.如图所示,AB ∥CD ,∠ABE=66°,∠D=54°,则∠E 的度数为_____度.19.下列三个命题:①对顶角相等;②全等三角形的对应边相等;③如果两个实数是正数,它们的积是正数.它们的逆命题成立的个数是_____.20.已知13a a +=,则221+=a a_____________________; 三、解答题21.已知一个多边形的内角和比其外角和的2倍多180°,求这个多边形的边数及对角线的条数?22.列方程解应用题某服装厂准备加工400套运动装,在加工完160套后,采用新技术,使得工作效率比原计划提高了20%,结果共用了18天完成任务,那么原计划每天加工服装多少套?23.先化简,再求值:222444211x x x x x x x ⎛⎫-++++-÷ ⎪--⎝⎭,其中x 满足2430x x -+=. 24.计算(1)212111x x x -⎛⎫-÷ ⎪--⎝⎭. (2)211a a a --- 25.如图所示90,A D AB DC ∠=∠=︒=,点,E F 在BC 上且BE CF =.(1)求证:AF DE =;(2)若PO 平分EPF ∠,则PO 与线段BC 有什么关系?为什么?【参考答案】***试卷处理标记,请不要删除一、选择题1.B解析:B【解析】【分析】设小组原有x 人,根据题意可得,出发时又增加了两位同学,结果每位同学比原来少分摊了3元车费,列方程即可.【详解】设小组原有x 人,可得:180180 3.2x x -=+ 故选B.【点睛】考查由实际问题抽象出分式方程,读懂题目,找出题目中的等量关系是解题的关键. 2.A解析:A【解析】分析:根据多边形的内角和公式计算即可.详解:.答:这个正多边形的边数是9.故选A.点睛:本题考查了多边形,熟练掌握多边形的内角和公式是解答本题的关键.3.D解析:D【解析】【分析】首先证明△ABC ≌△CDE ,推出CE=AC ,∠D=∠B ,由∠D+∠DCE=90°,推出∠B+∠DCE=90°,推出CD ⊥AB ,即可一一判断.【详解】在Rt △ABC 和Rt △CDE 中,AB CD BC DE =⎧⎨=⎩, ∴△ABC ≌△CDE ,∴CE =AC ,∠D =∠B ,90D DCE ∠+∠=o Q ,90B DCE ∴∠+∠=o ,∴CD ⊥AB ,D :E 为BC 的中点无法证明故A 、B 、C.正确,故选. D【点睛】本题考查全等三角形的判定和性质、解题的关键是熟练掌握全等三角形的判定和性质,属于基础题.4.B解析:B【解析】过E作EF∥AB,求出AB∥CD∥EF,根据平行线的性质得出∠C=∠FEC,∠BAE=∠FEA,求出∠BAE,即可求出答案.解:过E作EF∥AB,∵AB∥CD,∴AB∥CD∥EF,∴∠C=∠FEC,∠BAE=∠FEA,∵∠C=44°,∠AEC为直角,∴∠FEC=44°,∠BAE=∠AEF=90°﹣44°=46°,∴∠1=180°﹣∠BAE=180°﹣46°=134°,故选B.“点睛”本题考查了平行线的性质的应用,能正确作出辅助线是解此题的关键.5.C解析:C【解析】【分析】易得△AEP的等边三角形,则AE=AP=2,在直角△AEB中,利用含30度角的直角三角形的性质来求EB的长度,然后在等腰△BEC中得到CE的长度,则易求AC的长度【详解】解:∵△ABC中,∠BAC=90°,∠C=30°,∴∠ABC=60°.又∵BE是∠ABC的平分线,∴∠EBC=30°,∴∠AEB=∠C+∠EBC=60°,∠C=∠EBC,∴∠AEP=60°,BE=EC.又AD⊥BC,∴∠CAD=∠EAP=60°,则∠AEP=∠EAP=60°,∴△AEP的等边三角形,则AE=AP=2,在直角△AEB中,∠ABE=30°,则EB=2AE=4,∴BE=EC=4,∴AC=CE+AE=6.故选:C.【点睛】本题考查了含30°角的直角三角形的性质、角平分线的性质以及等边三角形的判定与性质.利用三角形外角性质得到∠AEB=60°是解题的关键.6.D解析:D【解析】【分析】由三角形内角平分线的交点到三角形三边的距离相等,可得三角形内角平分线的交点满足条件;然后利用角平分线的性质,可证得三角形两条外角平分线的交点到其三边的距离也相等,这样的点有3个,可得可供选择的地址有4个.【详解】解:∵△ABC内角平分线的交点到三角形三边的距离相等,∴△ABC内角平分线的交点满足条件;如图:点P是△ABC两条外角平分线的交点,过点P作PE⊥AB,PD⊥BC,PF⊥AC,∴PE=PF,PF=PD,∴PE=PF=PD,∴点P到△ABC的三边的距离相等,∴△ABC两条外角平分线的交点到其三边的距离也相等,满足这条件的点有3个;综上,到三条公路的距离相等的点有4处,∴可供选择的地址有4处.故选:D【点睛】考查了角平分线的性质.注意掌握角平分线上的点到角两边的距离相等,注意数形结合思想的应用,小心别漏解.7.D解析:D【解析】【分析】依据平行线的性质,即可得到∠1=∠DFG=40°,再根据三角形外角性质,即可得到∠2的度数.【详解】∵DF∥EG,∴∠1=∠DFG=40°,又∵∠A=30°,∴∠2=∠A+∠DFG=30°+40°=70°,故选D.【点睛】本题主要考查了平行线的性质以及三角形外角性质的运用,解题时注意:两直线平行,内错角相等.8.B解析:B【解析】【分析】原式利用多项式乘以多项式法则计算,根据乘积中不含x的一次项,求出m的值即可.【详解】(x+1)(2x+m)=2x2+(m+2)x+m,由乘积中不含x的一次项,得到m+2=0,解得:m=-2,故选:B .【点睛】此题考查了多项式乘以多项式,熟练掌握运算法则是解本题的关键.9.B解析:B【解析】【分析】通过平移后,根据长方形的面积计算公式即可求解.【详解】平移后,如图,易得图中阴影部分的面积是(a+3)(b+1).故选B.【点睛】本题主要考查了列代数式.平移后再求解能简化解题.10.B解析:B【解析】试题分析:由设原计划每天加工x 套运动服,得采用新技术前用的时间可表示为:160x天,采用新技术后所用的时间可表示为:()400160120%x -+天。
山东省济南外国语学校2019—2020学年度高一年级模块检测试题高一物理(满分:100分,时间:90分钟)第Ⅰ卷(选择题,共57分)一、单选题(共9个小题,每题3分,共27分,错选0分。
)1.(★)2019年1月3日10时26分,嫦娥四号探测器经过约38万公里,26天的漫长飞行后,自主着陆在月球背面,实现人类探测器首次在月球背面软着陆。
嫦娥四号着陆前距离月球表面100米处有一次悬停,对障碍物和坡度进行识别,并自主避障;选定相对平坦的区域后,开始缓速垂直下降。
最终,在反推发动机和着陆缓冲机构的“保驾护航”下,一吨多重的探测器成功着陆在月球背面东经177.6度、南纬45.5度附近的预选着陆区。
下面有关嫦娥四号探测器的说法正确的是( )A.嫦娥四号探测器从地球到月球的位移大小就是其运行轨迹的长度38万公里B.“3月10时26分”指的是时间间隔C.研究嫦娥四号探测器在月球着陆过程的姿态时,不可以将其看成质点D.嫦娥四号探测器在最后100米着陆过程中可以视作做自由落体运动1.考向位移与路程的区别、时间和时刻的区别、质点的认识和自由落体运动解析A:位移是初位置指向末位置的有向线段,故A错误。
B:3日10时26分指着陆的那个时刻,故B错误。
C:在研究探测器的姿势或者转动情况时,不能看成质点,故C正确。
D:在嫦娥四号着陆时速度近似为零,着陆前一定经历减速阶段,不是自由落体运动,故D错误。
答案 C点评 1.位移是矢量,有大小有方向,是初位置指向末位置的有向线段;路程是标量,是轨迹的长度;在单向直线运动中,位移大小等于路程。
2.时间间隔对应着时间轴上的一段距离,时刻是时间轴上的一点。
3.当物体的大小形状相对于所研究的问题可以忽略不计时,可以将物体看作质点。
当研究物体自身形状态姿势时,不能看成质点。
4.自由落体运动是初速度为零,加速度为g的匀加速直线运动。
2.(★)下列说法不正确...的是( )A.在不需要考虑物体本身的大小和形状时,用质点来代替物体的方法叫假设法B.我们有时会用比值法定义一些物理量,如平均速度、密度及加速度等C.根据速度定义知v=ΔxΔt ,当Δt极短时,ΔxΔt就可以表示物体在t时刻的瞬时速度,该定义应用了物理的极限法D.在对自由落体运动的研究中,伽利略猜想运动速度与下落时间成正比,并未直接用实验进行验证,而是在斜面实验的基础上进行理想化推理2.考向研究物理量的常见方法解析A:在不需要考虑物体本身的大小和形状时,把物体看成一个只有质量的点——质点,突出主要因素,忽略次要因素,这种方法叫理想化物理模型法,不叫假设法,故选A。
2020-2021济南外国语学校华山校区小学三年级数学下期中试卷及答案一、选择题1.下而各题的积最接近5600的是()。
A. 58×65B. 69×78C. 79×882.下面竖式计算正确的是()。
A. B. C.3.小学部有49个班,每班28人,小学部约有()人。
A. 800B. 1000C. 1200D. 1500 4.要使□2×23的积是三位数,□最大填()。
A. 5B. 4C. 35.下列算式中,()的商最接近50。
A. 155÷3B. 261÷5C. 149÷36.346÷6商的最高位是()。
A. 百位B. 十位C. 第二位7.用3、8、4、7组成一个除法算式,使商最大的是()。
A. 384÷7B. 837÷4C. 874÷38.黑板在教室的西面,那么同学们坐在黑板的()面.A. 东B. 南C. 西9.乐乐坐在欢欢的南面,明明坐在欢欢的东面,乐乐坐在明明的()面。
A. 西南B. 西北C. 东南10.晚上当你面向北极星时,你的右面是()方向A. 南方B. 西方C. 东方二、填空题11.做计算题时,小亮发现:两位数乘两位数,所得的积最多是________位数。
12.每套书有14本,王老师买了12套,一共买了多少本?小兰是这样列竖式计算的:13.复式统计表能反映________或________数据,它能更________地表示信息。
14.三年级同学在二月到六月份做好事的件数如下:二月20件;三月40件;四月30件;五月25件;六月35件。
将上面的数据填入下面的统计表。
①________②________ ③________ ④________ ⑤________ ⑥________15.□75÷6,当商是两位数时,□里最大能填________,当商是三位数时,□里最小能填________。
济南外国语学校华山校区2020年期中单元测试一、选择题1.如图所示,将棱长分别为a 、2a 、3a 的同一个长方体木块分别以不同的方式放置在桌面上,长方体木块的各个表面粗糙程度相同.若用弹簧测力计牵引木块做匀速直线运动,示数分别为F 1、F 2、F 3,则F 1、F 2、F 3之比为A .1∶1∶1B .2∶3∶6C .6∶3∶2D .以上都不对2.课间休息时,负责擦黑板的同学为方便老师下节课使用,将磁性板擦吸附在磁性黑板上如图所示,下列说法正确的是( )A .板擦受到四个力作用,其中有三个力的施力物体是黑板B .板擦受到的摩擦力大于重力C .作用在板擦上的磁力和弹力是一对相互作用力D .若磁力突然消失,板擦仍能保持静止不动3.做匀减速直线运动的质点,它的位移随时间变化的规律是224 1.5(m)x t t =-,当质点的速度为零,则t 为多少:( )A .1.5 sB .8 sC .16 sD .24 s4.下列叙述中不符合历史事实的是( )A .古希腊哲学家亚里士多德认为物体越重,下落得越快B .伽利略发现亚里士多德的观点有自相矛盾的地方C .伽利略认为,如果没有空气阻力,重物与轻物应该下落得同样快D .伽利略用实验直接证实了自由落体运动是初速度为零的匀速直线运动5.质点做直线运动的速度—时间图象如图所示,该质点A .在第1秒末速度方向发生了改变B .在第2秒末加速度方向发生了改变C .在前2秒内发生的位移为零D .第3秒和第5秒末的位置相同6.下列仪器中,不属于直接测量国际单位制中三个力学基本单位对应的物理量的是A.B.C.D.7.如图是A、B两个质点做直线运动的位移-时间图线,则A.在运动过程中,A质点总比B质点慢t t=时,两质点的位移相同B.当1t t=时,两质点的速度相等C.当1t t=时,A质点的加速度大于B质点的加速度D.当18.拿一个长约1.5m的玻璃筒,一端封闭,另一端有开关,把金属片和小羽毛放到玻璃筒里.把玻璃筒倒立过来,观察它们下落的情况,然后把玻璃筒里的空气抽出,再把玻璃筒倒立过来,再次观察它们下落的情况,下列说法正确的是A.玻璃筒充满空气时,金属片和小羽毛下落一样快B.玻璃筒充满空气时,金属片和小羽毛均做自由落体运动C.玻璃筒抽出空气后,金属片和小羽毛下落一样快D.玻璃筒抽出空气后,金属片比小羽毛下落快9.A、B、C三点在同一直线上,一个物体自A点从静止开始作匀加速直线运动,经过B 点时的速度为2v,到C点时的速度为6v,则AB与BC两段距离大小之比是A.1:3 B.1:8 C.1:9 D.3:3210.下列说法正确的是A.自由下落的石块速度越来越大,说明石块所受重力越来越大B.在空中飞行的物体不受重力作用C .一抛出的石块轨迹是曲线,说明石块所受的重力方向始终在改变D .将一石块竖直向上抛出,在先上升后下降的整个过程中,石块所受重力的大小与方向都不变11.一汽车在平直公路上做匀加速运动,在前2s 内的平均速度为10m/s ,在前6s 内的平均速度为22m/s ,则该汽车的加速度为( )A .6m/s 2B .4m/s 2C .3m/s 2D .12m/s 212.四辆小车从同一地点向同一方向运动的情况分别如图所示,下列说法正确的是A .甲车做直线运动,乙车做曲线运动B .在0~t 2时间内,丙、丁两车在t 2时刻相距最远C .这四辆车均从静止开始运动D .在t 1时刻甲乙两车瞬时速度相等13.小明从某砖墙前的高处由静止释放一个石子,让其自由落下,拍摄到石子下落过程中的一张照片如图所示,由于石子的运动,它在照片上留下了一条模糊的径迹.已知每层砖的平均厚度为6.0cm ,照相机本次拍照曝光时间为21.510s ,由此估算出位置A 距石子下落起始位置的距离为( )A .1.6mB .2.5mC .3.2mD .4.5m14.关于重力加速度的说法中,不正确的是( )A .在同一地点物体自由下落时的重力加速度与静止时的重力加速度大小一样B .在地面上不同的地方,重力加速度g 的大小不同,但它们相差不是很大C .在地球上同一地点,一切物体在自由落体运动中的加速度都相同D .重力加速度g 是标量,只有大小没有方向,通常计算中g 取9.8m/s 215.一个做匀减速直线运动的物体,先后经过a 、b 两点时的速度大小分别是4v 和v ,所用时间是t ,下列判断正确的是( )A .物体的加速度大小为5v tB .经过ab 中点时的速率是2.5vC .在2t 17vD .0﹣﹣2t 时间内发生的位移比2t ﹣﹣t 时间内位移大34vt 16.质点沿直线运动,位移—时间图象如图所示,关于质点的运动下列说法正确的是( )A .质点2s 末质点改变了运动方向B .质点在4s 时间内的位移大小为0C .2s 末质点的位移为零,该时刻质点的速度为零D .质点做匀速直线运动,速度大小为0.1m/s ,方向与规定的正方向相同17.如图所示,质量为m 的物块在与斜面平行向上的拉力F 的作用下,沿着水平地面上质量为M 的粗糙斜面匀速上滑,在此过程中斜面体保持静止,则地面对斜面体A .无摩擦力B .支持力大小为(m +M)gC .支持力大小为(M +m)g+FsinθD .有水平向左的摩擦力,大小为Fcosθ18.以下是必修课本中四幅插图,关于这四幅插图下列说法正确的是( )A .甲图中,赛车的质量不是很大,却安装着强劲的发动机,可以获得很大的惯性B .乙图中,高大的桥要造很长的引桥,从而减小桥面的坡度,目的是增加车辆重力垂直桥面方向的分力,保证行车方便与安全C .丙图中,传送带靠静摩擦力把货物送到高处D .丁图中,汽车轮胎的花纹不同会影响轮胎受到的摩擦力.地面与轮胎间的摩擦力越大汽车越容易启动,但是刹车越困难19.下列作直线运动的v-t 图象中,表示质点作匀变速直线运动的是( )A .B .C .D .20.从发现情况到采取相应行动经过的时间叫反应时间。
两位同学合作,用刻度尺可测得人的反应时间。
如图甲所示,A 握住尺的上端,B 在尺的下部做握尺的准备(但不与尺接触),当看到A 放开手时,B 立即握住尺。
若B 做握尺准备时,手指位置如图乙所示,而握住尺时的位置如图丙所示,由此测得B 同学的反应时间约为A .20sB .0.30sC .0.10sD .0.04s二、多选题21.物体沿一直线运动,在t 时间通过的路程为s ,在中间位置2s 处的速度为v 1,在中间时刻2t 时速度为v 2,则v 1与v 2关系为( )A .当物体做匀速直线运动时v 1=v 2B .当物体做匀加速直线运动时v 1>v 2C .当物体做匀减速直线运动时v 1>v 2D .当物体做匀减速直线运动时v 1<v 222.如图所示, 小球沿斜面向上做匀减速直线运动, 依次经a 、b 、c 、d 到达最高点e 。
已知ab =bd =10m ,bc =2m ,小球从a 到c 和从c 到d 所用的时间都是2s ,设小球经b 、c 时的速度分别为v b 、v c ,则( )A .v b =29m/sB .v c =3m/sC .cd :de =16∶9D .从d 到e 所用时间为5s23.如图所示,水平面上等腰三角形均匀框架顶角30BAC ∠=︒,一均匀圆球放在框架内,球与框架BC 、AC 两边接触但无挤压,现使框架以顶点A 为转轴在竖直平面内顺时针方向从AB 边水平缓慢转至AB 边竖直,则在转动过程中( )A .球对AB 边的压力先增大后减小B .球对BC 边的压力先增大后减小C .球对AC 边的压力一直增大D .球的重心位置一直升高24.关于竖直上抛运动的上升过程和下落过程(起点和终点相同),下列说法正确的是:( )A .物体上升过程所需的时间与下降过程所需的时间相同B .物体上升的初速度与下降回到出发点的末速度相同C .两次经过空中同一点的速度大小相等方向相反D .上升过程与下降过程中位移大小相等、方向相反25.如图所示,在斜面上有四条光滑细杆,其中OA 杆竖直放置,OB 杆与OD 杆等长,OC 杆与斜面垂直放置,每根杆上都套着一个小滑环(图中未画出),四个环分别从O 点由静止释放,沿OA 、OB 、OC 、OD 滑到斜面上所用的时间依次为t 1、t 2、t 3、t 4.下列关系正确的是( )A.t1>t2B.t1=t3C.t2=t4D.t2<t4三、实验题26.某同学利用图(a)所示的实验装置探究物块速度随时间的变化。
物块放在桌面上,细绳的一端与物块相连,另一端跨过滑轮挂上钩码。
打点计时器固定在桌面左端,所用交流电源频率为50 Hz。
纸币穿过打点计时器连接在物块上。
启动打点计时器,释放物块,物块在钩码的作用下推着纸带运动。
打点计时器打出的纸带如图(b)所示(图中相邻两点间有4个点未画出)根据实验数据分析,该同学认为物块的运动为匀加速运动。
比答下列问题:(1)打点计时器是直接测量________的工具(填可物理量的名称);在打点计时器打出B 点时,物块的速度大小为________m/s,在打出D点时,物块的速度大小为________m/s;(保留两位有效数字)m/s(保留两位有效数字)(2)物块的加速度大小为________227.“验证力的平行四边形定则”的实验如图甲所示,其中A为固定橡条的图钉,P为橡皮条与细绳的结点,用两把互成角度的弹簧秤把结点P拉到位置O。
弹簧秤的示数为F1、F2,为单独用一根弹簧拉到O点时的读数,F是用平行四边形法则求出F1、F2的合力。
(1)为了更准确得到合力与分力的关系,要采用作力的______(填“图示”或“示意图”)来表示分力与合力;(2)图甲中左侧测力计读数是________N(3)图乙中方向一定沿AO方向的力是________(填“F ”或“F′”)。
28.小华同学在做“研究匀变速直线运动”实验中,将打点计时器固定在某处,在绳子拉力的作用下小车拖着穿过打点计时器的纸带在水平木板上运动,如图所示。
由打点计时器得到表示小车运动过程的一条清晰纸带的一段。
如图所示,在打点计时器打出的纸带上确定出八个计数点,相邻两个计数点之间的时间间隔为0.1s,并用刻度尺测出了各计数点到0计数点的距离,图中所标数据的单位是cm.(1)根据纸带提供的信息,小华同学已知计算出了打下1、2、3、4、5这五个计数点时小车的速度,请你帮助他计算出打下计数点6时小车的速度6v=__________m/s(保留3位有效数字).计数点123456t0.10.20.30.40.50.6/s()1⋅0.3580.4000.4400.4850.530/v m s-(2)现已根据上表中的v、t数据,作出小车运动的v t-图象,如图所示。