22. It is no use _____to come now. He is busy.

　　　 A. ask him　　　 　　　B. to ask him　　　　 C. that you ask him　　 D. asking him

21. Charles Babbage is generally considered ______ the first computer.

　　　 A. to invent　　　　　 B. inventing　　　　　 C. to have invented　　 D. having invented

20. I was too excited ______ .

　　　 A. speak　　　　　　 B. to speak　　　　　 C. not to speak　　　　 D. speaking

19. "I usually go there by train."　　　　　 "Why not ______ by boat for a change?"

　　　 A. to try going　　　　 B. trying to go　　　　 C. to try and go　　　　 D. try going

18. "What do you think of the book?"　　　　 "Oh. excellent, it's worth _______ a second time."

　　　 A. to read　　　　　　 B. to be read　　　　　 C. reading　　　　　　 D. being read

17. People couldn't help ______ the foolish girl.

　　　 A. laugh at　　　　 B. to laugh at　　　　 C. laughing at　　　　 D. laughing　　　　 :

16. Excuse me for _____ in without ______.

　　　 A. coming, asking　　 B. coming, being asked　 C. to come, asking　 D. to come, being asked

15. Most of the students enjoy_____ stamps.

　　　 A. collect　　　　　　　 B. to collect　　　　　 C. collecting　　　　　 D. collected

14. We are looking forward to ______ another chance ______ it again.

　　　 A. be given, to try　　 B. give, to try　　　　 .C. giving, trying　　　 D. having, to try

13. You can keep the book until you ______ .

　　 A. have finished reading　　　　　　　　　　　 B. finish to read

　　 C. will finish reading　　　　　　　　　　　　 D. have finished to read