21. The fifth generation computers， with artificial intelligence， _C_ and perfected now.

　　A) developed B have developed C are being developed D will have been developed

　　22. This ticket _C_ you to a free meal in our new restaurant.

　　A gives B grants C entitles D credits

　　A，B两项都要加双宾语，结构为：gives / grants sb. sth.

　　entitle sb. to sth. 使某人有权得到某物; credit A to B 相信A是由B造成的。

　　相信飞机失事是由飞行员错误造成的。 Credit the crash to the pilot’s mistake.

　　crash 坠落，坠毁(专指飞机失事); collision 碰撞(强调两个物体碰撞，如火车、汽车等)。

　　we are sorry， very sorry， terribly sorry， awfully sorry.

　　23. You _D_ her in her office last Friday; she’s been out of town for two weeks.

　　A needn’t have seen B must have seen

　　C might have seen D can’t have seen

　　24. 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

　　have no choice but to do sth. 别无选择，只能做。..

　　25. 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

　　be attracted by 被…所吸引; be absorbed in 全神贯注(专注)于做…

　　be drawn in 被诱骗(诱使)做。.. ; concentrate on 专注于。

　　I was simply drawn in. 我是被诱骗上钩的。

　　27. 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

　　switch to another subject 转换话题; switch to another channel 转换频道。

　　28. It is politely requested by the hotel management that radios _C_ after 11 o’clock at night. [虚拟语气]

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

　　29. 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

　　view n. 景色，风景，视野，视域。