5．-Do you know why the chemical plant wasn't built here?

-Because it ______too much pollution to the air.

A．had caused B caused

C．will have caused D．would have caused

答案　D

解析　句意为：--你知道为什么这里没有建化工厂吗？--因为(如果建了化工厂)它对空气污染太严重。此处省略了从句，表示与现在事实相反，主句用would have＋过去分词，故选D。

6．-You are not allowed to keep the magazine too long.

-Don't worry. I just want to _____ it for some pictures.

A．refer to B．prefer to

C．look up in D．look into

答案　A

解析　句意为：--你不能借这本杂志太长时间。--别担心，我只是想查阅一些图片。如果选C项，则应用look up some pictures in it。Refer to查阅；prefer to更喜欢，宁愿；look up查阅；look into调查。由句意知A项正确。

7．__________ speed and flexibility，China's anti­ship missile CM­30 also has a greater destructive power than others in the market.

A．On the contrary to

B．Apart from

C．On behalf of

D．Little more than

答案　B

解析　句意为：除了速度和灵敏性，中国的反舰导弹CM－30比起市场上其他导弹更具有杀伤力。On the contrary to相反地；apart from除......之外，且不说，on behalf of代表，为了；little more than仅仅是。

8．Teachers recommend parents________ their children under 1 to ride bicycles to school for safety.

A．not allow B．do not allow

C．mustn't allow D．can't allow

答案　A