急!2道英语选择题~谢谢!1.There is some question__such a person lived a

急!2道英语选择题~谢谢!
1.There is some question__such a person lived at all.
A,concerning whether B, as to whether
答案选择的是B.能不能选择A?concerning的用法是什么?可以接从句吗?如果是about whether 是不是也可以?
2.when he returned home, he found everything in his room was___it had been the day he left 10 years ago.
A,as B, what C, like
选择哪个 为什么?
3.It turned out what her father left her was the plain ring. she ___happier if it had been diamonds.
A, shouldn't have been B, couldn't have been
答案选择B, 为什么不能选A.
盼复!谢谢!