1.选A.不定式表目的
2.选B.such as to固定搭配
3.选B.如果选A,主句的主语和从句的主语必须一致!但there be句型没有主语可以与exam的主语一致!
4.选C.there be句型和seems to do句型的混合
5.选C.对谓语动词seems反问,应用does,主语Fighting an artificial greenhouse effect应该用it指代,所以用doesn't it?
6.选B.After _____seemed an endless wait,在整个句中是充当时间状语的.而after后面应该接的是一个名词性从句.it不能用来引导名次性从句.所以只能用what.