18. A. wetter　　　 B. better　　 C. poorer　　 D. richer

17. A. few　　　　 B. little　　　 C. much　　 D. many

　 The problem of pollution is getting more and more serious.

　 Most people know there are four main kinds of __16__. For example, farmers use __17__ chemicals in their fields, so fields become __18__. This means soil pollution. People pour waste water into rivers and lakes, so the problem of __19__ pollution is becoming serious. Dirty air from factories and traffic vehicles __20__ people feel terrible. Most people also know about white pollution. It is caused by plastic bags. People can __21__ plastic everywhere in the streets. For quite a long time,　 people didn't’ __22__ that noise was a kind of pollution.　 In fact, it is __23__. People living near airports and factories often have hearing problems.

　 What is ____, no one seems to think that light pollution is a problem, __25__ it does have a bad effect on us.　 Then what should we do?

16. A. pollution　 B. industry　 C. action　　 D. protection

15.---Don’t you think making too much noise can ____ pollution?

　　　 --- Yes, I think so.

　 　A. cause　　 B. get　 C. reduce　 D. save

14.We have ____ homework every day. It takes nearly four hours to do it.

　　 A. mountains　 B. like mountains　 C. mountains of　 D. mountain of

13.Trees are important. They can _____ harmful gases and release oxygen.

A. get in　 B. take part in　 C. let in　 D. take in　

12. When we speak to people, we should be ______.

A. as polite as possible　　 B. as polite as possibly　

C. as politely as possible　 D. as politely as possibly

11. ---I think bananas taste much better than other fruit. Do you think so?

　　　 --- Of course! _______.

A. I prefer bananas, too　　 B. I don’t know　　

C. I don’t agree with you　 D. I never eat bananas

10.---Now most teenagers don’t like to talk with their parents.

--- Yes, but I am _____them. I like to talk with them ____ parents can give me valuable suggestions..

　 　A. different from; though　 B. the same as; though　

C. the same as; because　 D. different from; becasue

9.---Why don’t you think the air now is _____ that of 20 years ago?

　　 ---_______ it’s badly polluted by waste gases.

　 　A. as good as; Though　 B. as well as; Because　

C. as good as; Because　 D. as well as; Though