20. I don’t think he could have slept well last night,__________?

　 A. do I　 　　　　　　　 　　B. could he　 　　　　　 　　C. has he　 　　　　　　 　　D. did he

19. ----Shall I give you a ride as it is so late?

　 ---- Thank you. __________ .

　　 A. It’s up to you　 B. It couldn’t be better　 C. It all depends　 　　 D. If you prefer

18. ________ change your mind, do let me know.

A. If should you　 B. Should if you　 　　　　 C. Should you 　　　　　　 D. You should

17. _____ no need for us to discuss the problem again _____ it has been settled.

A. It has; once　 　　 B. It is; because　　　　　　 C. There had; for　 　　　　　　　 D. There is ; since

16. Some plants are so sensitive _____ pollution that they can only survive in a perfectly clean environment.

A. from　 　　　　　　 B. with 　　　　　　　　　　　 C. against 　　　　　　　　　 D. to

15. ---_______ you have an accident, who will look after you?

　 ----Can’t you look after me, dear?

A. Talk　 　　　　　　 B. Say　 　　　　　　　 C. Speak　 　　　　　　　　　 D. Discuss

14. The pond has been _______ a terrible smell for a month but nothing has been done.

　　　 A. calling in 　　　　　　　　 B. setting up　 　　　 　C. giving off　 　　　　　 D. giving in

13. _______ in his book, he didn’t notice me _____ I entered the room.

A. Devoted; when　 　　　 B. Absorbed; while　 C. Absorbed; when　 　 D. Devoted; while