《How Life Began On the Earth》

（完整版）Howlifebeganontheearth课文文本How life began on the earthNo one knows exactly how the earth began, as it happened so long ago. However, according to a widely accepted theory,the universe began with a “Big Bang” that threw matter in all directions. After that,atoms began to form and combine to create stars and other bodies.For several billion years after the “Big Bang”, the earth was still just a cloud of dust. What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. The earth became so violent that it was not clear whether the shape would last or not. It exploded loudly with fire and rock. They were in time to produce carbon, nitrogen, water vapor and other gases, which were to make the earth’s atmosphere. What is even mo re important is that as the earth cooled down, water began to appear on its surface.Water had also appeared on other planets like Mars but unlike the earth, it had disappeared later. It was not immediately obvious that water was to be fundamental to the development of life. What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas. This produced a chain reaction, which made it possible for life to develop.Many millions of years later, the first extremely small plants began to appear on the surface of the water. They multiplied and filled the oceans and seas with oxygen, which encouraged the later development of early shellfish and all sorts of fish. Next, green plants began to grow on land. They were followed in time by land animals. Some were insects. Others, called amphibians,were able to live on land as well as in the water. Later when the plants grew into forests, reptiles appeared for the first time. They produced young generally by laying eggs. After that, some huge animals, called dinosaurs, developed. They laid eggs too and existed on the earth for more than 140 million years. However, 65 million years ago the age of the dinosaurs ended. Why they suddenly disappeared still remains a mystery. This disappearance made possible the rise of mammals on the earth. These animals were different from all life forms in the past, because they gave birth to young baby animals and produced milk to feed them. Finally about 2.6 million years ago some small clever animals, now with hands and feet, appeared and spread all over the earth. Thus they have, in their turn, become the most important animals on the planet. But they are not looking after the earth very well. They are putting too much carbon dioxide into the atmosphere, which prevents heat from escaping from the earth into space. As a result of this, many scientists believe the earth may become too hot to live on. So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.。

Unit 4 How Life Began On The Earth----说课人：王华一、教学背景的分析1、教材内容分析本单元的中心话题是“天文学”，内容涉及太阳系、地球上的生命起源、宇宙大爆炸、月球探秘、黑洞效应等，主要内容围绕地球上生命的起源展开的。

本次阅读课“HowLife Began On The Earth ”通过对宇宙大爆炸理论进行科学性分析，推断出地球上生命的由来以及生物进化的过程。

2、学生背景分析“ How Life Began On The Earth 这一”话题虽然有趣，但本文的文体属于科普类说明文，内容抽象，用词多专业术语，阅读本文对高一学生来说有一定的难度。

不过本文以时间为线索，使得学生较易读懂本文的内容。

通过对本文的阅读，学生不仅可以了解地球上生命的起源以及发展过程，还可以掌握一些相关的语言知识。

二、教学目标的分析1.知识目标：（1）让学生在阅读中学到一些有用的单词和句子。

（2）让学生了解生命的起源。

2.能力目标：（1）提高学生的阅读技巧：略读，细读和对本文组织结构的分析（2）拓展学生对地球上生物进化的知识。

3.情感目标：（1）培养学生对科学的兴趣并激起学生对天文学的喜爱。

（2）调动和加强学生的环保意识。

三、重点难点的分析重点：激发学生学习兴趣，使学生完成阅读任务，理解文章内容。

难点：使学生通过播放录音及略读获取文章信息。

四、教法和学法的选择1、教学方法（1.）使用任务型教学与 PWP 教学法，让学生明确学习目标。

（2.）设计问答活动来检查学生对本文的了解。

（3.）让学生在讨论中学会合作学习。

（4.）分别利用个人、同桌和小组活动来完成学习任务。

2.学法（1.）合作学习 : 采用小组合作和组间交流等活动形式。

（2.）自主探究法 : 以学生为主体，培养学生自主探求问题的能力，主要通过相关图片、问题激活学生固有背景知识，使其自主分析、归纳、解决问题。

五、教学过程Step I Leading-in (1mins)Free talk with Ss:what is the end of the“world ”?What is the beginning of the“world ”?设计意图：以脑筋急转弯的形式引发本课的话题Step II Pre-reading (3mins)11.Each religion and culture has its own ideas about how life began on earth. What do you know?2.Are they true for the beginning of the life? Do you know what a scientific idea is?3.Read the title and look at the pictures. Can you predict what the reading will be about?设计意图：进一步激发学生的学习兴趣，激活其已有的知识，贴近了学生生活，又可以让学生对新单元的内容产生一种期待和渴望，使学生在心理上和认知上做好准备，激发他们对课文的学习兴趣并进行积极思考，从而培养其创造性的思维能力。

Unit 4 How life began on the earth教学设计【教学内容】How life began on the earth(人教新课标)·英语·高一(必修3) ·Unit 4 Astronomy:The science of the stars·Reading【教材分析】本单元的中心话题是“天文学”，内容涉及太阳系、地球上生命的起源、宇宙大爆炸、月球探秘、黑洞效应等，主要内容是围绕地球上生命的起源展开的。

How life began on the earth这篇阅读文章讲述了地球上生命的起源，所使用的文体是说明文。

文章通过对宇宙大爆炸理论进行科学性分析，推断出地球上生命的由来以及生物进化的过程。

【学情分析】教学对象为高一的学生。

经过高一上学期的英语学习，他们已经储备了一定的高中英语词汇和基础知识，认知和分析水平比初中阶段有了进一步的提高，能就给出的话题展开讨论，发表自己的看法，渐渐具备了用英语获取信息、处理信息、分析问题和解决问题的能力。

学生对“天文学”这一话题并不是很陌生，由于本篇阅读文章的脉络清晰、结构分明，读起来很有趣味，引人入胜，给学生留下了很大的思考空间，能够激发学生的想象力，积极去探索文意，了解生命的起源以及生物进化的过程。

所以在设计这堂课时，我重点从学生对“天文学”这一话题的兴趣出发，设计探究点，借助电影片段创设情景。

在合作探究的基础上，感悟、体验生命起源及生物进化过程的科学性。

【教学目标】1、能力目标：通过学习，使学生能读懂文章内容，理清文章脉络，总结地球上生命的由来以及生物进化的过程。

通过速读、细读和设计问题的引导，培养学生获取、分析和处理信息的能力。

创设问题情境，在质疑、探究的学习过程中，培养学生独立思考、推理、判断和创造性思维能力。

2、情感目标：通过学习本篇文章，让学生了解地球上生命的起源以及生物进化的过程，培养学生对科学的兴趣，激发学生探索科学的热情，以及增强学生保护地球的意识。

说课稿How life began on the earth?江苏省西亭高级中学栾爱春尊敬的各位老师：大家好！今天我说课的内容是新课标人教版必修三第四单元Reading部分。

一、材料分析1．教材的地位和作用从教材整合上来说，reading部分是本单元的中心环节，它既是本单元的基本语言内容的载体，又为本单元的知识拓展和综合语言运用奠定了坚实的基础，因此，上好reading部分既可以让知识的学习有一定的延续性，又可以为下面的教学做好铺垫，对完成本单元的教学也具有重要意义。

2．教材内容Reading部分讲述了地球上生命的起源，水的形成使得地球有别于其他星球，它使得地球上生命的诞生成为可能。

科学家认为，地球上的生命首先诞生于水中，上百万年后，陆地上才长出绿色植物，随后出现了陆栖动物和水陆西栖动物。

最初的动物产卵繁衍后代，后来出现了哺乳动物，人类也随之诞生了。

文章最后讲述的现象发人深省：The earth may become too hot for lives on it. 它关系到地球上生命的未来，值得教学这挖掘文本的内涵：那就是珍爱生命、珍爱地球。

3．教学目标1）知识与能力目标：1. 掌握reading部分中的重点单词和短语；2. 理解地球生命起源的过程；3. 能力简述地球的形成及生命的演变。

2）过程与方法目标：能运用略读、细读的策略；能学会借助语境理解生词的意义。

3）情感、态度与价值观目标：在理解地球与生物演变的基础上，充分意识到人人从我做起、从现在做起，用心珍爱生命、呵护地球。

人类是万物之灵，爱地球便是爱人类自己；通过本部分的学习，激发学生探究科学的热情，培养学生创造性思维,开拓想象空间。

4．教学重点和难点在本节的教学中，我把学生对本文的整体理解和把握作为重点，把语言表述能力作为难点，以听力为教学辅助手段，让学生感受英语语言之美，科学之美，激发他们的学习兴趣，为突破教学难点做好铺垫。

二、教材处理经由从整体到部分，再到整体的过程。

Paragraph 11. No one knows exactly how the earth began, as it happened so long ago. 该句中how 引导________从句，as引导________ 从句，it指代_________,happened可用_________来代替，整个句子译为____________________________________________。

2. However, according to a widely acc epted theory,the universe began with a “Big Bang” that threw matter in all directions.1) according to “根据”；“按照”2) began with :start with 由…开始,以…开始3）in all directions的意思是______________。

以下是direction的其它短语，请牢记。

in the direction 朝…方向；在…方向in the direction of 朝…方向，向…方向under the direction of 在…的指导下give directions 指示sense of direction 方向感from the direction of来自…方向in sb’s direction 朝某人的方向under sb's direction 在某人的指导下3 After that,atoms began to form and combine to create stars and other bodies.请同学们自己回忆总结other / the other / another / the others / others的用法。

Paragraph 21. What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe.该句中What引导________从句，when引导________ 从句，在句中_____语。