21. That was so serious a matter that I had no choice but _D_ the police.

　　A called in B calling in C call in D to call in

　　22. She was so _B_ in her job that she didn't hear anybody knocking at the door.

　　A attracted B absorbed C drawn D concentrated

　　23. At first, the speaker was referring to the problem of pollution in the country, but halfway in her speech, she suddenly _B_ to another subject.

　　A committed B switched C favoured D transmitted

　　24. It is politely requested by the hotel management that radios _C_ after 11 o'clock at night.

　　A were not played B not to play C not be played D did not play

　　25. Although I like the appearance of the house, what really made me decide to buy it was the beautiful _D_ through the window.

　　A vision B look C picture D view

　　26. Cancer is second only _B_ heart disease as a cause of death.

　　A of B to C with D from

　　27. The manager needs an assistant that he can _A_ to take care of problems in his absence. [in his absence 在某人不在场的情况下]

　　A count on B count in C count up D count out

　　28. The organization had broken no rules, but _A_ had it acted responsibly.

　　A neither B so C either D both

　　29. We gave out a cheer when the red roof of the cottage came _D_ view.

　　A from B in C before D into

　　30. They took _D_ measures to prevent poisonous gases from escaping.

　　A fruitful B beneficial C valid D effective

　　31. Doing your homework is a sure way to improve your test scores, and this is especially true _A_ it comes to classroom tests.

　　A when B since C before D after

　　32. Careful surveys have indicated that as many as 50 percent of patients do not take drugs _D_ directed.

　　A like B so C which D as

　　33. I hope all the precautions against air pollution, _D_ suggested by the local government, will be seriously considered here.

　　A while B since C after D as

　　34. In developing countries people are _C_ into overcrowded cities in great numbers.

　　A breaking B filling C pouring D hurrying

　　35. It's reported that by the end of this month the output of cement in the factory _A_ by about 10%. [output 产量]

　　A will have risen B has risen C will be rising D has been rising

　　36. If I had remembered _A_ the window, the thief would not have got in.

　　A to close B closing C to have closed D having closed

　　37. There are other problems which I don't propose to _A_ at the moment.

　　A go into B go around C go for D go up

　　38. Don't get your schedule _C_; stay with us in this class.

　　A to change B changing C changed D change

　　39. It is quite necessary for a qualified teacher to have good manners and _A_ knowledge.

　　A extensive B expansive C intensive D expensive

　　40. The patient's health failed to such an extent that he was put into _C_ care.

　　A tense B rigid C intensive D tight