20. -Turn off the TV, Jack. ____your homework now?

-Mum, just ten more minutes, please.

A. Should you be doing　　　 　 B. Shouldn't you be doing

　 C. Couldn't you be doing　　　 D. Will you be doing

19. -What do you think we can do for our aged parents?

-You ________ do anything except to be with them and be yourself.

A. don’t have to　 B. oughtn’t to　 C. mustn’t　 D. can’t

18. His lack of professional knowledge _______for the failure of the experiment.

A. accounted　　 B. explained　 C. counted　　 D. contributed

17. Not believing their eyes, the visitors on the spot _______ the flying plane, doing some most difficult and dangerous tricks in the sky.

A. glared at　 　　B. stared at　 　C. glanced at　 　D. caught sight of

16. Many festivals are held _______ our ancestors for their contribution to the world.

A. in honor of　 　　B. in the honor of　　 C. in memory to　 D. in the memory of

15.　 She promised to ______ at the meeting but she didn’t ______.

A. turn up; keep her word　 　　　 B. present; keep her promise　

C. attend; turn up　 　　　　　　　　　　　 D. appear; keep her words

14. In order to win back the customers, the owner of the restaurant decided to sell his food ____.

A. in a discount　 B. with discount　 C. at a discount　 D. for a discount

13. Most smokers say they _______ smoking to some degree but health experts suggest that they had better give it up ______ their health.

A. benefit; for the benefit of　　　　　　　 B. benefit from; with the benefit of　

C. receive goodness; in the benefit of　　　　 D. benefit from; for the benefit of

12. - Sorry to bother you.

- _____ You didn’t mean to, did you?

A. Forget it.　 B. You should say so.　 C. All right.　 D. Don’t say so.

11. Sir, you ______be sitting in this waiting room. It is for women and children only.

A. oughtn’t to　　　 B. can’t　　　　　 C. won’t　　　　 D. needn’t