20. While driving home, you ________ be careful enough.

　 A. can’t　　　　　　 B. mustn’t　　　　 C. shouldn’t　 　　 D. needn’t

19. It’s common in China now that both parents work, ___________ the grandparents raising their grandchildren.

　 A. leave　　　　 B. left　　　　　　 C. leaving　　　 D. leaves

18. The number of people who ______ killed in the earthquake _______ reached 30,000.

　　 A. was, has　　 B. were, has　　　　　　 C. were, have　　　 D. was, have

17. No one really thinks that the Internet will completely __________ the TV.

　　 A. take place of　　 B. take the place of　　　　 C. taken place of　 D. taken place

16. - Are you satisfied with what she has done about the job?

　 - Not at all．It couldn’t be __________．

　　 A. any worse　 B. any better　　 　　　 C. so worse　　 D. as good

15. ---You ought to have called him yesterday.

　 --- Yes, I know I __________.

　　 A. ought to　　 B. have to　　　　　 C. should have　　　 D. must have

14. Taking exercise regularly _____________ better fitness, less body fat and a drop in blood pressure.

　　 A. leads for　　　　 B. leads to　　　　 C. results from　　 D. cause

13. To feed his huge body, he eats an _________ 12,000 calories a day, six times the average for a man of his age.

　　 A. astonishment B. astonish　　　　 C. astonished　　　 D. astonishing