21. He is busy _______ for the exam.

　 A. prepare　　　　　　　　　 B. to prepare

　 C. prepared　　　　　　　　　 D.preparing

20. They looked forward very much to ________ him again.

　 A. be meeting　　　　　　　　 B. met

　 C. meeting　　　　　　　　　 D. meet

19. He enjoyed ________ the piano in the morning.

　 A. practising playing　　　　　 B. practising to play

　 C. to practise playing　　　　　 D. to practise to play

18. We mustn’t pretend _______ what we don’t know.

　 A. knowing　　　　　　　　　 B. having known

　 C. to know　　　　　　　　　 D. to be known

17. He likes _______ , but he doesn’t like ________ today because it is cold.

　 A. swimming, to swim　　　　 B. to swim, swimming

　 C. to swim, to swim　　　　　 D. swimming, swimming

16. The report was so _______ that they were all ________ .

　 A. moving, moving　　　　　 B. moved, moved

　 C. moving, moved　　　　　 　D. moved, moving

15. Don’t get ______ in the rain.

　 A. catch　　　　　　　　　　 B. caught

　 C. to catch　　　　　　　　　 D. catching

14. He seemed ______ nothing to take home that morning.

　 A. have　　　　　　　　　　 B. having

　 C. to have　　　　　　　　　 D. had

13. What I like most is _______ .

A.　　　 staying at home and doing nothing

B.　　　 staying at home and to do nothing

C.　　　 to stay at home and doing nothing

D.　　 to stay at home and to do nothing

12. What I wanted was_______ as quickly as possible.

　 A. giving it up　　　　　　 B. giving up it

　 C. to give up it　　　　　　 D. to give it up