19. ----I _____this morning, but he could not come.

　 ----Well, we’d better go and _____at his office.

A. called him; call on him　 　　　　　B. called on him; call him

C. called at him; call　　　　　　　　 D. called him; call at him

18. _____ from heart trouble for years, Professor White has to take some medicine with him wherever he goes.

A. Suffered　　　　　　　　　 B. Suffering　 　　

C. Being suffered　　　　　　　 D. Having suffered

17. ----_____I return the dictionary within three days?

----No, you_____. You_____ it for five days.

A. May; needn’t; can borrow　　　　　 B. Can; mustn’t; would have

C. Must; don’t have to; can keep　 　　　D. Shall; can’t; should read

16. Controlling water-pollution is necessary_____ it will be expensive.

A. so that　　　　 B. as if　　　　 　C. even though 　　D. ever since

15. Such a person _____ you talked about is seldom seen now.

A. that　　　　　　　 B. whom　　　　　 C. who　　　　　　 D. as

14. _______ the teacher’s instruction in the lab_____ important.

A. Following; are　　　 B. Following; is　　　　 C. Followed by; are　　　　　 D. To follow; are

13. E-mail, as well as telephones, ______ an important part in daily communication.

A. is playing　　　　　　　 B. have played　　　　　 C. are playing　　　　　　 D. play

12. Professor Wang has written some short stories, but he is______ known for his plays.

A. the best　　　　　　　　 B. more　　　　　 C. better　　　　　　　　　 　 D. the most

11. This is the very information _______ we can learn what is selling best in the market. .

A. from which　 　　　　 B. that　 　　　 　C. which 　　　 　D. from that

10. All _____ can be done has already been done.

A. /　　　　　　　　　　 B. what　 　　　　 　C. that　　　　　　 D. which