20. Teenagers　 　　　　their health because they play computer games too much.

A. have damaged　 B. are damaging　 C. damaged　 D. will damage

19. ---I am afraid I can’t return the book to you before Friday.

　　 --- 　　　　.

A.　　 Don’t be afraid　 B. Be careful　 C. Not at all　 D. Take your time

18. All people,　　 　they are old or young, rich or poor, have been trying their best to help those in need since the disaster.

A. even if　 B. whether　 C. no matter　 D. however

17. ---I can’t find my purse anywhere.

　　 ---You 　　　　have lost it while shopping.

　　 A. may　 B. can　 C.　 should　 D. would

16. 　　　　to reach them on the phone, we sent an email instead

　　 A. Fail　 B. Failed　 C. To fail　 D. Having failed

15. ----Where did you meet Mr. Bush?

　 ----It was at a conference______ a lot of reporters were waiting.

　 A. that　 　　　　　　　 B. which　 　　　　　　　　　　　 C. in which　 　　　 D. where

14. Don’t worry. It is _______. Drink ______ water and you will be well again.

　 A. nothing serious; plenty of　　　　　　 　　　　　　　 B. serious nothing; a large number of

　 C. nothing serious; a great deal　　　　　　 　　　　　　　 D. nothing serious; a plenty of