题目

I have no idea__that told me the fact,which helped me to solve the problem.
A.who was it B.who it was C.it was who D.it was whom
为什么

提问时间：2020-12-29

答案

CD先排除,语法不通,从句后面用肯定语序,所以选B,A明显是疑问语序.