1. Unit 4 Astronomy: the science of the stars the science of the stars

2. 1.When the water freezes in the cold weather, it will become solid. 2.After the earth explored violently, it produces the atmosphere which was made up of oxygen, nitrogen, carbon dioxide and some other gases. 3.It is generally believed it was the water that made the earth different from other planets.

3. 4.Too much carbon dioxide in the atmosphere prevents light from escaping from the earth into the space. 5.Whether life will continue on the earth will depend on whether the environment problem will be solved.

4. alternative words and expressions hard or firm using force to hurt or attack scientific study of the stars usually or widely stop …from natural large object that circles the sun the changes as plants or animals grow older burst The covering (of something) Way of doing things solid violent astronomy generally prevent from planet development explode surface method

5. Complete this passage with some of the above words. My friend Li Yanping was really very interested in ___________.He liked to watch changes in the moon,the only natural satellite of the earth through his telescope. One evening he thought he saw a huge comet ________as it hit the moon. The ________of the moon produced a lot of dust that became _______like a large ball. It seemed as if it would multiply and become a new _______.Li Yanping thought he was seeing the ______________of the universe until he noticed some dirt on his telescope!he was very disappointed. astronomy explode surface solid planet development

6. He is a great scientist living in East-Han Dynasty about 1800 years ago. He is the founder of astronomy, and the first man who studies earthquakes. Chinese people rebuilt his tomb in 1956 in honor of him. In 1977,a little planet in the solar system numbered 1082 was named after his name in order to remind people of his significant contributions for human.

7. Zhang Heng

8. What he did for human in astronomy will be remembered by all. How he observed the stars attracts me very much. Why he was interested in astronomy is unknown. What do the above sentences have in common ? 主语从句（ Noun Clauses as the Subject ）

9. 主语从句 用作主语的从句叫主语从句，它是名词 性从句之一。 What time I go to bed is fixed. Their destination is unknown. Where they are going is unknown. My bedtime is fixed.

10. 连词 that, whether ； 连接代词 who, what, which, whoever, whatever ； 连接副词 when, where, how 和 why 。 引导主语从句的连接词： 1.Light travels in straight lines. It is known to all. Combine the sentences into one: That light travels in straight lines is known to all.

11. 2.Will we hold a party in the open air tomorrow? It depends on the weather. Whether we will hold a party in the open air tomorrow depends on the weather. 3.What does he want? It is a book. What he wants is a book. 4.Which car will you choose to buy ? It makes no difference. Which car you will choose to buy makes no difference.

12. What rules have you learned? Which car you will choose to buy makes no difference. That light travels in straight lines is known to all. 谓语动词用单数 从句用陈述语序 不能省略关联词

13. 1 ） It + be + 形容词 + that- 从句 It is a pity that you missed the film. It is a fact (a shame, a pity, good news…) that… It is necessary (clear, true,strange, important …)that 2 ） It + be + 名词 + that- 从句 It is still uncertain whether he is coming or not. it 作形式主语的 that- 从句

14. 4) It + 及物动词（被动语态） + 主语从句 It has been decided that the exhibition will not open on Sundays. 3 ） It+ 不及物动词 + 主语从句 It seemed (happened, doesn’t matter, has turned out) that… It happens that they were absent.

15. Talk about problems in your study or life. The others should give some advice or suggestions. My advice is …… My suggestion is …… What I think about it is …… The fact is …… My advice is …… My suggestion is …… What I think about it is …… The fact is …… ……is my problem. ……is my trouble. ……is my difficulty. ……is my question.

16. 1. ____ you don’t like him is none of my business. A. What B. Who C. That D. Whether 2. ____ he said at the meeting astonished everybody present. A. What B. That C. The fact D. The matter C A

17. 4. _____ we’ll go camping tomorrow depends on the weather. A. If B. Whether C. That D. Where B 3. The Foreign Minister said, “____ our hope that the two sides will work towards peace.” A. This is B. There is C. That is D. It is D

18. 5. ____ leaves the room last ought to turn off the lights. A. Anyone B. The person C. Whoever D. Who 6. ___ is a fact that English is being accepted as an international language. A. There B. This C. That D. It C D

19. 7. ___ in the newspaper that the price of food will go up. A. It says B. It is said C. It has said D. He is said 8. It worried her a bit ________her hair was turning grey. A. while B. that C. if D. for B B

20. Write a short passage on the topic “My Problem”, making use of the subject clauses.