人教版必修3-Unit-4-How-Life-Began-on-the-Earth学案

1、人教版必修 3 Un it 4 How Life Began on the Earth学案学习目标：Learning the test学习课文教学重点： Get the ma in idea of the text 了解文章大意课前准备请同学们提前阅读学案容，了解课堂上要完成的任务，1准备17导学案2课本Page 25-26的课文Teachi ng Steps ；教学步骤Step 1 Have a check检查上节课的容Step 2 Learn the text of Page 25-26 学习 Page 25-26 课文1 Fast Readi ng关注课文中的数字，找出所发生的事件bil

2、li onyearsagoMany million years laterfor140millionyears65 million years ago2.6 million years ago2 Careful Reading仔细阅读课文 归纳段落大意Para 123 4 3 Careful reading 细读课文 完成排序AIn sects and amphibia nsappearedBDinosaurs appearedC The earth became a solid ballD Small pla nts grew on the waterE Reptiles appearedF

3、Plants began to grow on dry landG The earth was a cloud of dustH Water appeared on the earth.I Shellfish and other fish appearedJ The un iverse began with a BIG BANGK Clever ani mals with hands and feet appearedL MammalsappearedStep 3 Th ink思考Is it wrong or right to show films with dinosaurs andpeop

4、le together? Why?在课文中找到适宜的语句，或根据自己的 理解答复此题Step 4 A quit of the text 当堂检测，课文容填空The uni verse bega n with a .At that time, theearth was.The n, the earth became.After that, water appeared on the earth and rew on the water .Then, shellfish and other fishappeared . Next,began to grow on dry land andin se

5、ctsa ndamphibians. Later,reptilesa nddino saursappeared.Last,cleverani mals ppeared and spread all over the earth.Thus,the human become the most important animals on the earth .However; they are not look ing after the earth well. They areputting too muchcarbon dioxide into the , whichprevents heates

6、caping from the o space. Sowhether life will continue on the earth for millions of yearsto comewill on whether this problem can be solved.Step4课文知识点1. In our solar system eight planets circle around the sun.在我们的太阳系里，八大行星绕着太阳运转。solar system 太阳系八大行星：Uran us 天王星、Ven us金星、Earth地球、Mars 火星、Mercur

7、y 水星、Jupiter木星、Neptune 海王星、Saturn 土星2. Can you match the names with the planets?Matchto/with 将配对，与相匹配Match the words with the destinations.把这些词与释义相连。3. The origin of life on earth is a question that interestsastronomers.地球上生命的起源是一个使天文学家感兴趣的问题。the origi n of life生命的起源 that in terests astro no mers定语从

8、句4. According to a widely accepted theory, the universe began with a “ Big Bang that threw matter in all directi on s.一种普遍为人们所承受的理论是：宇宙起源于一次大爆炸，这次大爆炸将物质投 射到四面八方。a widely accepted theory一种普遍为人们所承受的理论beg in/start with 以 开始 end up with 以完毕A thousand Li journey starts/begins with the first step.千里之行，始于足

9、下。5. The earth was still a cloud of dust. 一团尘埃6. What it was to become was uncertain until between 4.5 and 3.8 million years ago whe n the dust settled into a solid globe.随后它会变成什么没人能知道，直到38-45亿年前，这团尘埃才慢慢地形成一个 固体的球状物。What it was to become主语从句be to do sth常用来表示不可防止将要发生的事。As a young man he didn ' t

10、know he was to win world fame later on.年轻时，他不知道自己日后会举世闻名。settle in/into sth安排下来；习惯于新居；适应新工作settle dow n安静下来，平静下来7. It exploded loudly with fire and rock.They were in time to producecarb on, n itroge n, water vapour and other gases, which were to makethe earth ' s atmosphere.它地球猛烈的爆炸喷出了烈火与岩石，最终产生

11、了碳、氮气、水蒸气和其它 多种气体，从而形成了地球的大气层。in time 与时最终，迟早You will learn how to do it in time.你迟早能学会做这件事。The doctor came just in time.医生与时地赶至 U 了。which were to make the earth ' s atmosphere. 非限制性定语从句8. What is even more more important is that as the earth cooled down waterbegan to appear on its surface.更为重要的

12、是，地球冷却了下来，地球的表面就开始出现了水。What is eve n more more importa nt主语从句cool down变凉，冷却下来as 随着后面加从句=with加名词或动名词As time goes by, I get used to the weather here.=With time going by, I get used to the weather here.随着时间的进展，我习惯了这儿的天气。9.It was not immediately obvious that water was to be fun dame ntal to the developm

13、e nt of life.水会对生命的开展起关键作用，这一点在当时并不是很明显。It is obvious that =lt is clear that 彳艮明显It is obvious that you are wrong.很显然，你是错误的。10. What many scientists believe is that the continued presenee of waterallowed the earth to dissolve harmful gases and acids into the oceans and seas.很多科学家相信，由于地球上长期有水存在，使地球得以

14、把有害气体和酸性物质 溶解在海洋里。What many scie ntists believe主语从句that引导的是表语从句allow/permit sb to do sth允许某人做某事allow/permit doing sth允许做某事dissolve harmful gases and acids into the ocea ns and seas.把有害气体和酸性物质溶解在海洋里。dissolveinto 把溶解在11. They produced young gen erally by laying eggs.它们一般是通过孵蛋而繁衍后代的。by doi ng用于说明做某事的手段

15、、方式。He used to make his liv ing by painting.他以前是靠画画为生。12. They are putt ing too much carb on dioxide into the atmosphere, which preve nts heat from escap ing from the earth into space.他们把过多的二氧化碳释放到大气层中，这使得地球上的热不能释放到太空中 去。which preve nts heat from escap ing from the earth into space.非限制性定语从句preve nt/

16、stop (from)doi ng sth 阻止做某事=keep from doing sthHis heart trouble didn ' t prevent him (from) going to class the next day. 他的心脏病没能阻止他第二天去上课。Noth ing can preve nt their pla ns (from) being carried out.什么也不能阻止他们的方案得以实施。13.So whether life will continue on the earth for milli ons of years tocome will depe