what is even more unbelievable是主语从句，从句中连接词what作主语，意思是"...的（事）"。wh-类连接词引导主语从句时在从句中充当句子成分并有词义，主要作主语，宾语，表语和状语等。

What you are doing is very difficult. 你正在做的事很难。

例 1. Nearly all educators agree that a challenging situation can often _____ the best qualities of a person.

A. bring out

B. bring up

C. bring in

D. bring about

解析：句意：几乎所有的教育家都认为，一个有挑战性的环境经常能够显示一个人最好的品质。本题考查动词短语辨析。A意为"出版，阐明，使显现"；B意为"抚养"；C项意为"引进，吸引"；D项意为"导致，引进。根据句意选A。

答案：A。

例 2. Putin has won the Russia's presidential election as expected, over which many hold the opinion that he _____ it in terms of his contribution to the country.

A. permits

B. deserves

C. admits

D. preserves

解析：句意：像预料的一样，普京赢得了俄罗斯的总统大选，对此许多人认为，就他对国家的贡献而言，这是他应得的。permit意为"允许"；deserve意为"应得"；admit意为"承认"；preserve意为"保留"，根据句意应选择B项。

答案：B。

例3. It was a real race _____ time to get the project done. Luckily, we made it.

A. over

B. by

C. for

D. against

解析：句意：完成这项工程真的是在与时间赛跑。幸运的是，我们成功了。本题考查介词辨析。over意为"在...上面"；by意为"被，经过"；for意为"支持，赞成"；against意为"反对，违背"。

答案：D。

例4. I agree with your statement _____ principle but I disagree on some details.

A. with

B. for

C. to

D. on