Question

【题目】—The air in Jinan used to be seriously polluted. But now it is really clean and fresh.

—Our government ________ much to improve it. Happiness is achieved through hard work.

A.doesB.didC.has doneD.will do

Answer 1

【答案】C

【解析】

句意：——济南的空气过去被严重污染。但现在它真的又干净又新鲜。——我们的政府已经做了很多改进。幸福是通过努力工作获得的。

A. does做，第三人称单数；B. did做，过去式；C. has done已经做了，现在完成时；D. will do将做，一般将来时。根据But now it is really clean and fresh.及下文Happiness is achieved through hard work.可知这里是用现在完成时态，其结构是have /has done的形式。根据题意，故选C。