2. Unit 4 How Life Began on the Earth

3. theory atom billion globe violent carbon atmosphere unlike fundamental n. 学说；理论 n. 原子 n. （英 ) 万亿； ( 美）十亿 n. 球体；地球仪；地球 adj. 猛烈的；强暴的 n. 碳 n. 大气层；气氛 prep. 不同；不像 adj. 基本的；基础的 Words preview

4. harmful acid chain multiply oxygen exist thus dioxide carbon dioxide adj. 有害的 n. 酸 n. 链子；连锁；锁链 vi. & vt. 乘；增加 n. 氧 vi. 存在；生存 adv. 因此；于是 n. 二氧化物 二氧化碳 Words preview

5. in time lay eggs give birth to in one’s turn prevent…from 及时；终于 下蛋 产生；分娩 轮到某人；接着 阻止；制止 Expressions preview

6. Skimming to get general ideas

7. Skimming Reading Comprehension I 1. Who knows how life began on the earth exactly? A. Scientists. B. Astronomers. C. No one. D. Aliens ( 外星人 ). 2. What does “small clever animals” refer to? A. Insects. B. Reptiles. C. Dinosaurs. D. Humans.

8. Careful reading to solve difficult points

9. 1. in time 及时 ; 终于 in time (for sth/ to do sth)= not late a. The car came to a stop just in time to prevent an accident. 汽车及时停下，避免了一场车祸。 b. Can we get to the station in time? 我们能及时到达车站吗？

10. 2. laying eggs 下蛋 The hens are not laying well at the moment. 现在那些母鸡不爱下蛋。 lay, lie 区别 lay vt (laid, laid, laying) 把东西放平 ; 下蛋 lie vi (lay, lain, lying) 平放 lie vi (lied, lied, lying) 撒谎

11. What prevented you from joining us last night? 昨晚什么事使你不能参加我们的晚会 ? 阻止某人做某事 : prevent sb. (from) doing sth. stop sb. (from) doing sth. keep sb. from doing sth. 3. prevent...from 阻止 ; 制止 We must prevent the disease (from) spreading. 我们一定要防止疾病蔓延。

12. Read the passage quickly to find the main idea of each paragraph.

13. Read the passage carefully and analyse its structure. Write down the main idea for each paragraph. Paragraph 1 : Paragraph 2: Paragraph 3: Paragraph 4: Paragraph 5:

14. Paragraph 1: A widely accepted theory about the formation of the universe Paragraph 2: The formation of the earth Paragraph 3: The importance of water for life Paragraph 4: The development of plants and animals on the earth Paragraph 5: The arrival of humans and their impact on the earth

15. Scanning to get detail information

16. 1. The earth was different from the other planets in that__________. A. a cloud of dust was around the earth B. comfortable climate remained on the earth C. water remained on the earth D. carbon remained on the earth scanning Reading Comprehension II

17. 2. The plants grew before the animals because they provide__________. A. nutrients for animals to absorb( 吸收 ) B. oxygen for animals to breathe C. necessary temperature for animals to keep warm D. water vapour for animals

18. 3. Which of the following statements is true? A. The dust settled into a solid globe between 4.5 and 3.6 billion year ago. B. The first small plants began to appear on the surface of the land. C. About 2.6 million years ago some small clever animals appeared and spread in the ocean. D. Dinosaurs died out long before human beings developed on the earth.

19. Put the order of development of life into a timeline. Use the reading passage to help you. 1 Insects and amphibians appeared. 2 Dinosaurs 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. scanning Reading Comprehension III

20. 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 animals with hands and feet appeared. 12 Mammals appeared. Answer: 10 7 3 8 4 9 6 1 5 2 12 11

21. Detailed Reading The development of the earth

22. Stage 1: The development of the earth (1) After the Big Bang, what happened? a cloud of dust a violent solid ball

23. exploded with fire and rock produced water vapour and gases (2) What happened next?

24. (3) What did the water vapour and gases form? the earth’s atmosphere

25. Water appeared which is important for the beginning of life on the earth. (4) What appeared on the earth then?

26. (5) What did the water form? oceans and seas

27. 1. Big Bang (a huge explosion around 15 billion years ago) 2. a cloud of energetic dust 3. a ball moving around the sun 4. exploded with fire and rock 5. produce the water vapour, carbon dioxide… How did the earth come into being?

28. 6. cooled down 7. water appeared 8. harmful gases were dissolved

29. The development of life

30. arrival of small plants in water (1) What life developed after water appeared? early shellfish Stage 2: The development of life in water

31. all sorts of fish (2) What life developed in water next?

32. green plants on land insects on land (3) What life developed after the life in water?

33. amphibians on land and in the water forests Stage 3: The development of life on land (1) What life developed next on land?

34. reptiles on land dinosaurs on land (2) What life developed after forests appeared?

35. mammals on land (3) What life developed after dinosaurs?

36. small clever animals (4) What life developed after mammals?

37. Can you say the sequence of development of life on the earth after detailed reading? water water plants shellfish fish land plants land insects amphibians

38. forests reptilesdinosaurs mammals clever animals

39. DM: SC: Read the passage again and underline all the discourse markers (DM) and sentence connectors (SC). however, after that, next, later, finally, thus, as a result of this and, but, because, or

40. Design an activity on Earth Day What is the activity is about? Why is the activity is designed? When and where is the activity? Who takes part in the activity? What is to be done in the activity? … How can we protect the earth and make it a better place to live on?

41. Quiz

42. Translation Quiz I 1. ____________________ ( 它会变成什么 ) was uncertain until between 4.5 and 3.8 billion years ago. 2. It was not immediately obvious that ______________________________ _________________ ( 水会对生命的发展 起关键作用 ). 3. ___________________________________ ( 为什么恐龙会突然灭绝 ) still remains a mystery. What it was to become water was to be fundamental to the development of life Why the dinosaurs suddenly disappeared

43. 1. ______ he referred to in his article was unknown to the general reader. （ 2007 上海卷） A. That B. What C. Whether D. Where Quiz II

44. 2. ______ parents say and do has a life- long effect on their children. （ 2007 陕西卷） A. That B. Which C. What D. As

45. 3. It has been proved ____ eating vegetables in childhood helps to protect you against serious illnesses in later life. (2008 上海卷 ) A. if B. because C. when D. that

46. 4. ______ we are sure about is the need to prevent children from being spoiled. (2008 上海春卷 ) A. What B. Which C. Whether D. That

47. 5. ______wants to stay in a hotel has to pay their own way. (2008 浙江卷 ) A. Anyone B. The one C. Whoever D. Who

48. Homework 1. Search the Internet for information of the development of life and find more solutions to global warming. 2. Finish the exercises on page 28.