Lecture 2 . 数词+介词
请将下列语句翻译成英文：
1.该电路中的电流为电源短路电流的一半。
●The current in the circuit is one half of the short-circuit
current of the source.
2.现在其内部的压力是原先的1/3。
●Now its internal pressure is one third what it was.
3.月球的质量为地球的1/81。
●The mass of the moon is one eighty-first that of the earth.
4.这个元件上的电压为零点几伏特。
●The voltage across this component is several tenths of a
volt.
5.这种蓄电池的电阻仅为零点零零几/千分之几欧姆。
●The resistance of this kind of storage battery is only a few
thousandths of an ohm.
6.其误差为6/1012。
●Its error is six parts in 1012.
7.这台计算机储存的信息比那台多3倍。
●This computer stores four times more Information than
that one.
8.不久的将来对这种设备的需求量将为现在的20倍。
●The demand for this equipment in the near future will be
twenty times what it is.
I. 分数与倍数
1．一般表示法：
●分子--基数词；分母—序数词
●8/9: eight ninths , 1/81: one eighty-first
2．“零点几”、“零点零几”、“千分之几”，”百万分之几”…
●The voltage across this component is several tenths of
a volt.
●The pill weighs a few hundredths of a gram.
●This is only a few thousandths of the heat of
vaporization.
●Seven parts per million
●Seven parts in a million
●Seven parts in 106.
3．数词在句子中作前置修饰语
●The output is 100 times {of} the input.
●Its speed is three times that of the light.
●The force excerted on the body is two fifths what it was. 4．表示数量增长/减少的常用句型
1．n times + 比较级=n times as 原级as
●This box is six times heavier than that one.
●This value is nearly 4.5 times greater than the ideal one.
●The wavelength of this musical note is over three times
longer than that of the same note in the air.
●The sample has been magnified by a factor of 11. （增了
10倍，为原来的11 倍）
●If the radius is halved, the flow rate is reduced by a
factor of 5. （降低了4倍，降为原来的1/5）
请根据中文原文改正英文译文的错误。
1.【中文原文】这个电容器上的电压为零点零几伏。
【英文译文】The voltage on this capacitor is several
hundredths of a volt.
2.【中文原文】这个物体比那个重4倍。
【英文译文】This object is five times heavier than that one is.
II. Seven fairy ladies: 七个常用介词
1．Of
i.Of+ 抽象名词：语气更强烈的形容词
a)The book will be of help > helpful in exposing computer
scientisit to the latest technology.
b)This measurement is of great precision > precisely .
c)It is of no use > useless grounding this point.
ii.Of+ 可数名词复数：在…之中among
d)Of all these instruments, this one is the most expensive.
e)Of all the three parameters, two can be disposed quickly.
iii. A of B: 表示A、B为同位、主谓或动宾关系
f)The concept of potential difference will be introduced in
section II.
g)The lighter machine part has a mass of 7 kg.
h)The failure point corresponds to a safety factor of 1.
i)Ellipse are used to describe the motion of the planets
around the sun.
j)The variation of the output with the input is shown in Fig.2.
k)The seperation of gold from its ore is not easy.
l)The resolution of a force into x- and y-components is possible.
m)Exposure of the body to a toxic substance should be avoided.
2．With
i.With+ 具体名词：表示”用…”或“与…”或”具有…”
a)Power can be measured with =by using a wattmeter.
b)This line is parallel with the x-axis.
c)This is a function with two variables.
ii.With+ 抽象名词：语气更强烈的副词
d)AC can be changed into DC with great ease = very easily.
e)This parameter can be measured with
accuracy=accurately .
iii.vary, change, increase, decrease等动词+ with…：随着…
f)The conductivity of a semiconductor varies with
temperature.
g)The ship’s speed decreases with the increase of the water
resistance.
iv.with 位于句首，可表示“对于，有了，在…情况下”
h)With rockets, things are different.
