19. The flu is believed ___ by viruses that like to reproduce in the cells inside the human nose and throat.

A. causing　　　　 B. being caused　 　　　C. to be caused　　　 D. to have caused

18._____much advice I gave him, he did exactly what he wanted to do.

A. How 　　　　B. However　　　　 C. No matter 　　　D. whatever

17． ____ and I’ll get the work finished.

A. Have one more hour　　　　　　　 B. One more hour　

C. Given one more hour　　　　　　　 D. If I have one more hour

16．---Tom, would you please lend me some paper?

---Sorry, mine _____.

A. was used up　　　 B. ran out　 C. have given out　 D. has run out

15．It was　　 back home after the experiment． -

　 　 A. not until midnight did he go　　 　　　　　　　　　　　　　　　　　　 B. until midnight that he didn’t go

　 　 C. not until midnight that he went 　　　　　　　　　　　　　　　　　　 D. until midnight when he didn’t go

14. The new building will be built _________ was a wasteland 30 years ago.

A. in which　　 　 B. where　　　 C. in what　 　　D. there

13. The young elephants each ________ as ______ as 200 kilograms , and that old one is three times as _____

A. weighs; much ; heavy　　　　　　　 B. is weighed; many ; much

C. are weighed ; many; much　　　　　 D. weigh ; much ; heavy

12. --- Catherine, I have cleaned the room for you.

　 --- Thanks. You _____ it. I could manage it myself.

A. needn’t do　　 B. needn’t have done　 C. mustn’t do　 D. shouldn’t have done

11. The Parkers bought a new house but ___ will need a lot of work before they can move in.

A. they　　　　 　B. it　　　　　　 C. one　　　　　 D. which

10. I'd rather you did some housework when you are free, but you ____.

　 A. don't　　　　　 B. didn't　　　　 C. wouldn't　　　 D. weren't