人教必修三unit4课文精讲.ppt

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1、Module III Unit 4Astronomy抄写as a result结果as a result of.由于.的结果too.to.太.而不能.depend on依赖，取决于look after照顾prevent.from(doing).阻止.做.escape from.逃离.in ones turn轮到某人，接着be different from.与.不同give birth to.产生；分娩lay eggs 下蛋allow doing 允许做某事允许做某事 allow sb.to do 允许某人做某事允许某人做某事 be allowed to do 被允许做某事被允许做某事be fu

2、ndamental to 对.是重要的in time 及时 on time 按时according to 根据begin with起源于in all directions=朝四面八方1.Whats the meaning of the word“Astronomy”?I.Warming upthe science of stars;the scientific study of stars and planets.2.What words will you think of when we talk about this topic?star,planet,the sun/moon/earth

3、,solar system 恒星恒星 行星行星 太阳太阳 月球月球 地球地球 太阳系太阳系 3.How many planets are in the solar system?8PlutoScientists now think Pluto is too small to be called a planet.The Solar System11115.The names of eight planets.MercuryVenusEarthMarsJupiterSaturnUranusNeptune1)水星水星2)金星金星3)地球地球4)火星火星5)木星木星6)土星土星7)天王星天王星8)海

4、王星海王星II.Pre-reading1.Have you ever asked your mother,“Mom,where do I come from”?2.Nearly everybody has this or that puzzles:How do human beings come into being?How does the earth come into being?3.In China,there are two legends about these puzzles.Do you know the names?盘古开天辟地盘古开天辟地 女娲补天造人女娲补天造人 4.In

5、 the western culture,who creates everything in the world?The GodThe GodIII.Fast-reading1.Do you believe in such stories?Are they based on science?2.In this unit,well learn something more scientific.3.Whats the title of the text?4.From the title,we can predict that the text may tell us the origin of

6、life on the earth.How life began on the earthHow life began on the earth5.Lets enjoy a short video.生命进化史HOW LIFE BEGAN ON THE EARTH地球上生命的起源No 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 m

7、atter in all directions.After that,atoms began to form and combine to create stars and other bodies.没有人确切知道地球是怎样开始形成的，因为在很早很早以前它就形成了。然而，一种普遍为人们所接受的理论是：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。然后，原子开始形成并结合成恒星和其他天体。1.according to 根据2.widely accepted 广泛接受的3.began with=start with 起源于，开始于4.in all directions=朝四面八方句型句型

8、begin with/start with 以以开始，从开始，从着手着手仿写仿写 认识从实践开始。认识从实践开始。Knowledge_.begins with practice 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

9、 earth became so violent that it was not clear whether the shape would last or not.It exploded loudly with fire and rock.大爆炸后好几十亿年过去了，但地球还只是一团尘埃。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。地球（开始）变得激烈动荡，不知道这个固体形状是否会继续存在下去。它（地球）猛烈的爆炸喷出了烈火与岩石。It was not clear whether.“是否.是不清楚的”，it 是形式主语，whether从句为真正的主语

10、，即Whether the shape would last or not was not clear.what 引导的主语从句，what 作become 的表语，when引导的是定语从句，引导的是定语从句，修饰修饰between 4.5 and 3.8 billion years ago。一团不确定的，certain确定的vi.持续vilent 激烈的，violence暴力2.What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a

11、solid globe.1._（使大家吃（使大家吃惊的是）惊的是）is that he didnt come to the meeting.What surprised everybody 2._（他所做的）（他所做的）added to our difficulty.What he did _ we cant get seems better than _ we have.A.What;what B.What;that C.That;that D.That;what_ made the school proud was _ more than 90%of the students had be

12、en admitted to key universities.A.What;because B.What;that;C.That;what D.That;becauseABThey were in time to produce carbon dioxide,nitrogen,water vapour and other gases,which were to make the earths atmosphere.What is even more important is that as the earth cooled down,water began to appear on its

13、surface.最终产生了碳、氮气、水蒸气和其他多种气体，从而形成了地球的大气层。更为重要的是，地球冷却了下来，地球的表面就开始出现了水。in time 及时；终于 in time to do sth 及时做某事，来得及做某事on time 按时What is even more important is that.更为重要的是.cool down 凉下来，冷却定语从句2.What is even more important is that as the earth cooled down，water began to appear on its surface.(P26 L13)句式分析句

14、式分析句中句中what引导的是一个引导的是一个_，what 做做从句主语，从句主语，that引导的是一个引导的是一个_，as引导的是一个引导的是一个_。时间状语从句时间状语从句主语从句主语从句表语从句表语从句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.在火星这些其他行

15、星上都出现了水，但和地球不同的是，这些水后来都消失了。水会对生命的发展起关键作用，这一点在当时并不明显。be fundamental to 对.是重要的 It 是形式主语，真正的主语是是形式主语，真正的主语是that water was to be fundamental to the development of life.It is/was(not)obvious that.是（不）明显的，如:It is no wonder that he has passed the exam.What many scientists believe is that the continued pres

16、ence 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.很多科学家相信，由于地球表面上长期有水存在，它使得地球得以把有害气体和酸性物质溶解在海洋里。这就产生了一系列的反应，使得生命就有可能开始发展了。the continued presence of water 水的长期存在allow vt.允许、许可、容许允许、许可、

17、容许allow doing 允许做某事允许做某事 allow sb.to do 允许某人做某事允许某人做某事 be allowed to do 被允许做某事被允许做某事主语从句that引导表语从句continued 持续不断的连锁反应which引导定语从句be harmful to 对对有害有害 do harm to sb.=do sb.harm 伤害某人，对某人有害处伤害某人，对某人有害处 1)Pollution is especially harmful to animals.2)Smoking will do you a lot of harm.Stage 1:The developme

18、nt of the earth(1)After the Big Bang,what was the earth like?a cloud of dust a solid globe exploded with fire and rock produced water vapour and gases(2)What happened next?(3)What did the water vapour and gases form?the earths atmosphere Water appeared(4)What appeared as the earth cooled down?water

19、is important for the beginning of life on the earth.Why is water so important for the beginning of life?Because water allowed the earth to dissolve harmful gases into oceans and seas.？Many millions of years later,the first extremely small plants began to appear on the surface of the water.They multi

20、plied and filled the oceans and seas with oxygen,which encouraged the later development of early shellfish and all sorts of fish.好几百万年以后，水的表面开始出现了极小的植物。它们繁殖起来就使得早期的海洋充满了氧气，这为早期的贝类及其他各种鱼类的发育进一步创造了条件。在.的表面引导定语从句各种各样的Next,green plants began to grow on land.They were followed in time by land animals.Som

21、e were insects.Others,called amphibians,were able to live on land as well as in the water.接着，绿色植物开始出现在陆地上。随后，陆地上出现了动物，其中有一些是昆虫，另外一些叫两栖动物，它们既能在陆地上生活，也能在水里生活。也，又，还被称为两栖动物Later when the plants grew into forests,reptiles appeared for the first time.They produced young generally by laying eggs.After that

22、,some huge animals,called dinosaurs,developed.They laid eggs too and existed on the earth for more than 140 million years.后来当这些植物长成森林时，爬行动物第一次出现了。它们一般是通过孵蛋来繁衍后代的。再后来一些叫做恐龙的巨型动物出现了。它们也生蛋，在地球上生存了一亿四千多年。14.They produced young generally by laying eggs.它们一般是通过孵蛋而繁衍后代的它们一般是通过孵蛋而繁衍后代的.Lie,lie,lay 的区别如下的区别如

23、下:动词原动词原形形第三人第三人称单数称单数过去式过去式 过去分过去分词词现在分现在分词词中文释中文释义义 lieliesliedliedlying撒谎撒谎;谎话谎话 lie lieslaylainlying躺躺;位位于于 laylayslaidlaidlaying放置放置;下蛋下蛋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

24、 mammals on the earth.然而，六千五百万年前，恐龙时代结束了。它们为什么会突然灭绝至今仍是个谜。恐龙的灭绝使地球上哺乳动物的产生有了可能。appear-disappearappearance-disappearanceThese animals were different from all life forms in the past,because they gave birth to young baby animals and produced milk to feed them.这些动物不同于以往所有的生命形态，因为它们能从体内生产出幼仔并给幼仔哺乳。be dif

25、ferent from.与.不同give birth to.产生；分娩比较两处的form,“atoms began to form”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.最后，大约260万年前，一些小巧聪明、长着手脚的动物出现了，它们

26、散布在地球的各个地方。于是，他们接着成为了这个行星上最重要的动物。in ones turn轮到某人，接着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.然而，他们对地球却并不怎么在意。它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。look after照顾prevent.from

27、(doing).阻止.做.escape from.逃离.16.They are putting too much carbon dioxide into the atmosphere,which prevents heat from escaping from the earth into space.阻止某人做某事阻止某人做某事:prevent sb.(from)doing sth.stop sb.(from)doing sth.keep sb.from doing sth.As a result of this,many scientists believe the earth may b

28、ecome 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.因此很多可科学家相信地球可能会因此变得太热而不适合生物的生存。所以，在未来的数百万年中，生命能否在地球上延续取决于这个问题能否得到解决。as a result结果as a result of.由于.的结果too.to.太.而不能.depend on依赖，取决于主语从句宾语从句Stage2 The dev

29、elopment of life small plants appears in water 1.What life developed after water appeared?Shellfish and all sorts of fish 2.What life developed in water next?green plants began to grow on land insects appeared3.What about the life on land?amphibians on land and in the waterforests4.What life develop

30、ed next on land?reptiles appeared dinosaur developed 5.What life developed after forests appeared?mammals on land6.What life developed after dinosaurs?small clever animals7.What life developed after mammals?1.Who are the small clever animals with hands and feet?2.Are they taking care of the earth we

31、ll?Why?Because they are putting too much carbon dioxide into the atmosphere,which prevents heat from escaping from the earth into space.The earth may become too hot to live on.The earth is becoming hotter and hotter!1.Insects and amphibians appeared.3.The earth became a solid ball.5.Reptiles appeare

32、d.7.The earth was a cloud of dust9.Shellfish and other fish appeared.11.Clever animals with hands and feet appeared2.Dinosaurs appeared.4.Small plants grew on the water.6.Plants began to grow on dry land.8.Water appeared on the earth10.The universe began with a“Big Band”.12.Mammals appeared.83109115

33、1741262Can you put the order of development of life into a time line?Ex.2 on P271.There is a _(fundament)difference in attitude between these two politicians.2.He didnt believe in the _(exist)of God.3.Its_(like)him not to say hello;as he is a man in good manners.4.It is_(harm)to your eyes to read in bed.五、词形变换五、词形变换 用所给词的适当形式填空。用所给词的适当形式填空。harmfulfundamentalexistenceunlike