book3unit4Astronomy全单元课件.ppt

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1、Unit 4solar system太阳系太阳系Hangzhou Foreign Languages School Bao Xiaoming The Solar SystemThe Solar System1111SunVenusMercuryMarsJupiterSaturnEarthPlutoNeptuneUranus But scientists now think Pluto is too small to be called a planet.Different ideas about how life beganBig BangPangu (盘古盘古)GodNuwaLets rev

2、iew the evolution of life on the earth. After the “Big Bang”, the earth was full of water.Original cells appeared in the ocean. The cells in the water began to separate. Marine animals came into being. Some animals (amphibian & insects) came to land.Reptile appeared. dinosaurs mammalsMan had evolved

3、 from apes. They developed new methods of growing food, hunting and moving around. As time went by, they covered the earth and have become the most important animals on the planet.We are making the world better.We are making the world worse.ABDiscussion new methods of growing food(1) What humans dev

4、eloped?new methods of hunting new methods of moving aroundGreenhouse effect(2) But they are not taking care of the earth very well. What problem are humans causing? make the earth too hot put too much carbon dioxide into the atmosphere Too much carbon dioxide is being put into the atmosphere.The ear

5、th may become too hot to live on. The earth is becoming hotter and hotter!Hangzhou Foreign Languages School Bao Xiaoming As young people, what little things can we do for the earth? solar energy plant trees recycle rubbish prevent desertificationsave water purify airWhether life will continue on the

6、 earth depends on human beings.Only if we care will we help,only if we help shall all be saved!Hangzhou Foreign Languages School Bao Xiaoming 人教版高中英语选修三Unit 4Reading_The Solar System Do you know how life began on the earth? Do you know any ancient idea about the beginning of the universe?ReadingHOW

7、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 sever

8、al 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

9、loudly with fire and rock. They were in time to produce carbon, 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 surface. Water had also appeared on other planets like Mars but

10、 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

11、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 sort

12、s 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 general

13、ly 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 pos

14、sible 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

15、 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

16、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.How life began on the earth?Reading1. What is the original earths atmosphere made up of? 2. What is fundamental to the developme

17、nt of life?3. Which kind of life-being first appeared on the earth, plants or animals? 4. Main idea of each paragraphScanningScan the passage quickly to answer the following questions.Scan the passage quickly to answer the following questions. Carbon, nitrogen, water vapour, and other gases.Water.1.

18、 What is the original earths atmosphere made up of?2. What is fundamental to the development of life?3. Which kind of life-being first appeared on the earth, plants or animals? Why? At first, small plants began to appear on the surface of the water, they produced oxygen, which encouraged the later d

19、evelopment of early shellfish and all sorts of fish.4. Choose the main idea for each paragraph ( ) The arrival of humans and their impact on the earth. ( ) The formation of the earth. ( ) The development of plants and animals on the earth. ( ) A widely accepted theory about the formation of the univ

20、erse. ( ) The importance of water for life.54213HOW 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

21、 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 cle

22、ar whether the shape would last or not. It exploded loudly with fire and rock. They were in time to produce carbon, 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 surface. _

23、_ _ _ 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 harm

24、ful 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 enco

25、uraged 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, repti

26、les 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 disa

27、ppeared 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

28、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, whic

29、h 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. _ _ _ _ _ _ _ _ _1. Why was the e

30、arth different from other planets? The water remained.2. Why did the plants grow before the animals came? Because plants provide oxygen for animals to breathe. Answer the questions.3. Why is it wrong in films and stories to show dinosaurs and people together? Because dinosaurs died out long before h

31、uman beings developed on the earth.4. There used to be nine planets in the solar system. Recently scientists have decided that one of them can no longer be considered a planet. Do you know the name of that planet? Do you know why they removed it? Pluto. Scientists now think it is too small to be cal

32、led a planet. 5. Why do you think that humans are the cleverest animals on the earth? They are the cleverest animals because they have larger brains than any other creature on the earth so far.6. What problem is caused by human beings? They cause global warming. 1. Why was the earth different from o

33、ther planets? A. It produced a lot of heat. B. The water remained. C. The water disappeared. D. It was the oldest planet.Choose the best answer. 2. Why was life able to develop on the earth but not on other planets? A. The earth had a solid shape. B. The earth did not have harmful gases in its atmos

34、phere. C. The water stayed on the earth but not on other planets. D. The earth was not too hot and not too cold. 3. Why was it necessary for plants to grow before animals? A. Animals needed plants to protect them from the sun. B. Plants provided oxygen for animals to breathe. C. Animals could hide f

35、rom hunters in the forest. D. It was easier for plants to grow. 4. It can be inferred from the text that _. A. after “Big Bang”, what the dust was to become remained a mystery B. plants appeared before the animals C. plants multiplied and filled the oceans with oxygen D. plants played an important p

36、art in the appearance of the animals Passage structureMain bodyPara 1: Para 2:Para 3:Para 4: Para 5: A widely accepted theory about the formation of the universe.The formation of the earth.The importance of water for life.The development of plants and animals on the earth.The arrival of humans and t

37、heir impact on the earth.Read the passage carefully and analyze its Read the passage carefully and analyze its structure:structure:earth, atmosphere and waterlife development on the earthhuman beingsPage 27a cloud of energetic dust a solid ballatmosphere a world full of water4132combine into explode

38、 with fire and rockdissolve harmful gases Cool down plants in the watershellfish and fishplants on landinsects and amphibiansreptiles dinosaurs mammals They produced young by l_ eggs.ayingThey _ young baby animals and produced milk to feed them.gave birth toDinosaurs e_ on the earth for more than 14

39、0 million years.xistedSeveral billion years after the “Big Bang”Between 4.5 and 3.8 billion years agoa cloud of dusta solid globeexploded with fire and rockWater began to appearproduce C/N water vapor, etc.Stage1 The development of the earth Stage1 The development of the earth Why is water so import

40、ant for the beginning of life? Because water allowed the earth to dissolve harmful gases into oceans and seas.Stage2 The development of lifeStage2 The development of lifeRead Para. 4-5 and fill in the blanks.456 7 8 910small plants in watersmall plants in water insectsinsects reptiles reptilesamphib

41、iansamphibiansmammalsmammalsdinosaursdinosaurs humanshumansplantsanimalsgreen plants on landgreen plants on landforestsforestsshellfish and all shellfish and all sorts of fishsorts of fish321Evolution of life on the earth （ ） 1 Insects and amphibians appeared. （ ） 2 Dinosaurs appeared. （ ） 3 The ear

42、th became a solid ball. （ ） 4 Small plants grew on the water. （ ） 5 Reptiles appeared. （ ） 6 Plants began to grow on dry land. （ ） 7 The earth was a cloud of dust. （ ） 8 Water appeared on the earth. （ 9 Shellfish and other fish appeared. （ ）10 The universe began with a “Big Bang”. （ ）11 Clever anima

43、ls with hands and feet appeared. （ ）12 Mammals appeared.5106）2948371 Detailed readingPut the order of development of life into a time line. 12 11 Page 27Post reading After reading the passage, discuss the following After reading the passage, discuss the following questions.questions.1. Why was the e

44、arth different from the other planets?2. Why did the plants grow before the animals came? Because the water remained on the earth. Because plants provide oxygen for animals to breathe.Page 273. Why is it wrong to show films with dinosaurs and people together? Because dinosaurs died out long before h

45、uman beings developed on the earth.4. There used to be nine planets in the solar system. Recently scientists have decided that one of them can no longer be considered a planet. Do you know the name of the planet? Do you know why they removed it? The name is Pluto. Scientists now think it is too smal

46、l to be called a planet.Page 275. What problem is caused by human beings?Global warming.Page 27Page 27_ 语篇标识词：在理解句与句之间的关系时，把握语篇标识词(discourse markersdiscourse markers)是最基本的技巧之一。语篇标识词是指在上下文中起连接作用，表明句与句之间逻辑关系的词语。如表示举例关系的for example, for instance;for example, for instance;表示转折关系的but, however, although;b

47、ut, however, although;表示因果关系的because, since;because, since;表示顺承关系的so, andso, and和表示对比关系的while, whereas, in while, whereas, in contrastcontrast等。常见的常见的语篇标志词语篇标志词 (逻辑关系词逻辑关系词)1. 表示并列关系 likewise, once again / once more, in (much) the same way (manner), similarly / similar to, also / as well as, not onl

48、y but also , both and , neither nor , like / just like, as / just as, equally namely, or, and2. 表示转折关系 but / yet / whereas, however, otherwise, in contrast (to), conversely, though / although, nevertheless, unlike, in spite of, despite, on the contrary, even if / even though, on the one hand , on th

49、e other hand ; instead(of), not as as , rather than, even so, while3. 表示举例 for example / for instance / e.g., such as, that is / namely / i.e., in other words, in general / in particular, especially, specifically4. 表示因果关系 as a result, as a consequence, consequently, so / therefore / thus, then, for

50、this reason, hence, accordingly, because / because of, owing to, thanks to, on account of, since, due to, for, as, this is why5. 表示递进关系 and, then, as well as, again, another, also / too, in addition (to), additionally, additional, besides, moreover, furthermore, not only but also , whats more6. 表示让步