The guests ______ finally arrived.
问题描述：
The guests ______ finally arrived.
A.we had been waiting for B.whom we had been waiting
C.for who we had been waiting D.who had been waiting for
我认为A和D都是可以的呀（如果错的话,错在哪呢?正确的应该选什么呢?我题目做晕掉了``` OMG~
答
A正确
D 应该改为 who WE had been waiting for