必修三Unit4Reading How Life Began on the EarthPPT精品文档

1、B3 Unit 4 Astronomy: the science of the stars.the scientific study of the universe and the heaven bodies (such as the sun, the moon, and stars), gas, and dust within it. .In our solar system eight planetscircle around the sun. The Solar System. 地球地球 _ 木星木星 _ 火星火星 _ 水星水星 _ 海王星海王星 _F. 土星土星 _G. 天王星天王星

2、_H. 金星金星 _EarthJupiterMarsMercuryNeptuneSaturnUranusVenusThe Solar SystemThe Solar SystemCan you name the eight planets? Pluto(冥王星冥王星)? a dwarf planet.In our solar system eight planetscircle around the sun. 1111B3 Unit 4 Reading：How life began on the earth.Warming upWarming up.Chinese Legends (传说传说)

3、 Pangu separates the sky from the earth.His whole body then turns into all kinds of things in the universe.Legend: The Goddess Nuwa mended the heaven and created human beings from the clay(粘土粘土). According to Bible (圣经圣经), God created the world and the first man, Adam (亚当亚当) and the first woman, Eve

4、 (夏娃夏娃). The Western Religious Beliefs .How life began on How life began on the earththe earth.skimmingskimmingPara. 1Para. 2 Para. 3 Para. 4 Para. 5 The formation(形成形成) of .The importance of for life.A widely accepted theory The development of onthe earth.The arrival of on the earth. the Big Bangth

5、e earthwaterplants and animalshumans and their impact. How does the author develop the passage? Task 1:Task 1: Give examples（举例）（举例） In time order（以时间顺序）（以时间顺序）C. Comparison（比较）（比较）.Whats the writing style of the text?A. Narrative 记叙文B. Explanation 说明文C. Essay 散文Task 2:Task 2:.1. What is the origina

6、l 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? ScanningScan the passage quickly to answer the following questions.Scan the passage quickly to answer the following questions. Carbon, nitroge

7、n, water vapour, and other gases.Water.1. 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 pro

8、duced oxygen, which encouraged the later development of early shellfish and all sorts of fish.More details.time the earthAs the earth cooled downSeveral 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 appear

9、produce C/N water vapor, etc.Stage1 The development of the earth (p1-3)Stage1 The development of the earth (p1-3). Why is water so important for the beginning of life? Because water allowed the earth to dissolve harmful gases into oceans and seas.Stage2 The development of life(p4-5)Stage2 The develo

10、pment of life(p4-5).Read Para. 4-5 and fill in the blanks.456 7 8 910small plants in water insects reptilesamphibiansmammalsdinosaurs humansplantsanimalsgreen plants on landforestsshellfish and all sorts of fish321Evolution of life on the earth. （ ） 1 Insects and amphibians appeared. （ ） 2 Dinosaurs

11、 appeared. （ ） 3 The earth 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 B

12、ang”. （ ）11 Clever animals 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 27.1. Why was the earth different from other planets? The water remained.2. Why did the plants grow before the animals came?

13、Because plants provide oxygen for animals to breathe. .3. Why is it wrong in films and stories to show dinosaurs and people together? Because dinosaurs died out long before human beings developed on the earth.4. There used to be nine planets in the solar system. Recently scientists have decided that

14、 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 called a planet. .5. What problem is caused by human beings? They cause global warming. .The development of the earth and the lif

15、e on the earth. .a cloud of dust a solid globeatmosphere: carbon, nitrogen, water and other gases water4132settled into explode with fire and rockdissolve harmful gases and acids Cool down .small plants in the waterearly shellfish and fishgreen plants on landinsects and amphibians .insects and amphi

16、biansreptiles dinosaurs mammals .reptiles 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 140 million years.xisted.Man had evolved from apes. Thats the development of life.Thats the de

17、velopment of life.Greenhouse effectThe earth is our only one home. Are we taking good care of the earth? What problems are humans causing ?putting too much carbon dioxide into the airthe earth may become too hotNo life will be on the earthdiscussiondiscussion.As a student, what little things can we

18、do for the earth?. solar energy plant trees recycle rubbish prevent desertificationsave water purify air.We have only one earth!We should take care of the earth!.Only if we care shall we help！Only if we help will all be saved!.B3 Unit 4 Learning about language.Page 28_.Page 28.Page 28fundamentalastr

19、onomygave birth toexistedAs a resultatomspreventsfrompuzzle.Page 28.Page 29.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 t

20、hat, 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

21、 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 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

22、to appear on its surface. 1 _2 _ 3 _.HOW LIFE BEGAN ON THE EARTH 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 con

23、tinued 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 multip

24、lied 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 i

25、n 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

26、 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. 4

27、 _ 5 _6 _.HOW LIFE BEGAN ON THE EARTH 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. Th

28、ey 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 wheth

29、er this problem can be solved. 7 _.Page 29 _ _ _ _ _ _.Page 29 _143526 _ _ _ _ _ _B3 Unit 4 workbook page63.Page 63blocking outbroke outgave outsold outwatch outhang outwatch out / look out phrasal verb 紧急情况下提醒某人当心e. g. Youll become an alcoholic if you dont watch out. Watch out! You nearly hit that

30、car. Look out! Theres a train coming! Watch it! You nearly knocked my head off with that ladder.watch (out) for sth. phrasal verb to pay close attention in a particular situation because you are expecting sth. to happen or you want to avoid sth. bad 注意e. g. She stepped outside to watch for the cab.

31、(等) What problems should I watch out for when buying an old house? (当心、留心)forforfor.Page 63religionsreligiouslikeunlikegentlegentlypresentationpresent.Page 63Page 63 Now that we have finished the design, the company, in its turn, will do the construction._ The fire did not cause too much damage, bec

32、ause the firefighters arrived in time._ The spaceship was pulled very close to the satellite by its strong gravity._ The sandstorm led to a chain reaction which ended in a serious train crash.Page 63_ _ The atmosphere in the classroom relaxed after the teachers humorous talk cheered us up._ Dont dis

33、turb her. She gave birth to a boy last night and now she is asleep._ Most of the evidence are destroyed. Thus, its impossible to prove that the drug is harmful._ Clouds are masses of very small drops of water that float in the sky.Page 63existedliveddeveloped protectfromclimatemultipliedweather prev

34、ent from_ _ _ _ _ _Climate is what we expect, weather is what we get. Mark Twain .Page 646273154what was believed by many scientistswhat was suggested by Einstein _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Your appearance will remind others where and how you are living. You know your children are growing up when

35、 they stop asking you where they came from and refuse to tell you where theyre going. 从句可得是主谓结构哦！从句可得是主谓结构哦！.Page 64you have not received your invitation to the party yetmany people who ride bicycles do not look where they are going The only way to keep your health is to eat what you dont want, drin

36、k what you dont like, and do what youd rather not. Mark Twain I know where Im going and I know the truth, and I dont have to be what you want me to be. Im free to be what I want. Muhammad Ali B3 Unit 4 Using language .the natural force that causes an object to move toward the centre of the earth. Gr

37、avity.Isaac NewtonAlbert EinsteinStephen HawkingGravity.Isaac Newton 16421727. 牛顿牛顿经典物理学理论体系的建立者。经典物理学理论体系的建立者。 16651665年创立微分；年创立微分；16661666年开始研究积分。年开始研究积分。16661666年年, ,开始想到研究重力开始想到研究重力(gravity)(gravity)问题，问题，苹果落地的传说，也是在此时发生的轶事。苹果落地的传说，也是在此时发生的轶事。其一生的重大科学思想是在这两年期间其一生的重大科学思想是在这两年期间（2222至至2323岁）岁形成的。岁

38、）岁形成的。16691669年，把年，把自自然哲学的数学原理然哲学的数学原理，宇宙体系宇宙体系) )等等手稿送到剑桥大学图书馆收藏。晚年研究手稿送到剑桥大学图书馆收藏。晚年研究宗教。宗教。.Albert Einstein（18791955）. 爱因斯坦爱因斯坦在量子论、分子运动论、相对在量子论、分子运动论、相对论论(Theory of Relativity)等物理学的三等物理学的三个不同领域取得了历史性成就，特别个不同领域取得了历史性成就，特别是狭义相对论的建立和光量子论的提是狭义相对论的建立和光量子论的提出，推动了物理学理论的革命，他对出，推动了物理学理论的革命，他对社会进步事业也有重要贡献

39、。社会进步事业也有重要贡献。.Stephen Hawking born in 1942 . 斯蒂芬斯蒂芬藿金藿金是当今科学界的一位传奇是当今科学界的一位传奇性人物。这不仅仅因为他是一位被誉性人物。这不仅仅因为他是一位被誉为继爱因斯坦后最著名的科学思想家为继爱因斯坦后最著名的科学思想家和最杰出的理论物理学家，还在于他和最杰出的理论物理学家，还在于他是在常人无法想象的身体状况下进行是在常人无法想象的身体状况下进行研究和创造性工作的。研究和创造性工作的。.A The text is about how three scientists wanted to find out about the beg

40、inning of the universe.B The text is about how the idea of gravity has developed over a long periods of time.C The text is about the important of three scientists and their work.Listen to the tape and choose the best summary of the listening text.Listen to the tape again and fill thechart belowIsaac

41、 NewtonAlbert EinsteinStephen HawkingIdeaDevelopment .Isaac NewtonAlbert EinsteinStephen HawkingIdea Large bodies have a force which pulls thing towards them.In space large objects make space and time bend; the larger the objects; the further space and time bends.Black holes have a very large mass and pull things towards them towards their edge.Isaac NewtonAlbert EinsteinStephen HawkingDevelop-mentThe bigger the object the stronger the gravity.Time goes slower in very strong gravity.If you go over the edge, you cannot get out; but