20. --- I think the waiter has forgotten us. We ________ here for over half an hour!

　 --- I think you’re right. He probably thinks we have already ordered.

　　　 A. are waiting　　　　　　　　　　　　　　 　 　　　　 B. have been waiting

　　　 C. have waited　　　　　　　　　　　　　　　　　　　　　 　 　 D. will wait

19. When she woke up, she realized that things she had dreamed about could not _______ have happened.

　　　 A. possibly　　　　　　 B. exactly　　　　　　　 　 C. certainly　　　 　　　 D. usually

18. Mr. John was always _______ the poor and the sick, often providing them with free medical care.

　　　 A. tended by　　　　　 B. absorbed in　　　　 　 C. reminded of　　　 D. concerned about

17. --- Jim, do you have the time?

　 --- _______.

　 --- Never mind. Thanks anyway.

　　　 A. Of course, I do. The time is 10:30

　　　 B. Sure. But I’m afraid it’s too late for me

　　　 C. Yes, it’s half past nine

　　　 D. Sorry, but I left my watch home

16. In his address at two-day APEC Economic Leaders Meeting, President Hu _______ the APEC to reform itself to raise the efficiency of cooperation so as to keep advancing _______changing times.

　　　 A. called in; for　　　　　　　　 　　　　B. called on; with

　　　 C. called for; at　　　　　　　　 　　　D. called at; through

15. His proposal is _______ to all of us and you do not need to tell us more about it.

　　　 A. apparent　　　　　　　　　 B. practical　　　　　　 C. reasonable　　　　　　　　 D. abrupt