20. Turn on the television or open a magazine and you _____ advertisements showing happy, balanced families.

A. are seeing　　　　　　　　　　　　　　　 B. will see 　　　　　　　　　　　　

C. see　　　　　　　　　　　　　　　　　　　　 D. have seen

19. The ability to store knowledge makes computers different from every other machine _______ invented.

A. ever　　　　　　　　　 B. thus　　　　　　　　　 C. yet 　　　　　　　　　 D. as 　　

18. The little man was _______ one metre fifty high, who is often laughed at.

A. almost more than　　　　　　　　　　　　　 B. hardly more than 　

C. nearly more than　　　　　　　　　　　　　　　　　 D. as much as

17. When I try to understand ________ that prevents so many Americans from being as happy as one might expect, it seems to me that there are two causes.

A. why it does　　　　　　　 B. what it does　　　　　　　 C. what it is　　　　　 D. why it is

16. The news has just ______ that the president is going to visit China next month

A. come down　　　　　　　 B. come up　　 　 　 C. come out　　　　　 D. come about

15．How can you expect him to make any improvement 　　 you never give him an opportunity to have a try？

　　　 A．unless　 　　　　　　　 B．when　 　　　　　　　 C．until　 　　　　　　　　 D．while