题目内容：

After I had walked for six hours,___.
A.I had been tired out B.I was tired out
C.I'll be tired out D.I would have been tired out
选什么答案,为什么?

优质解答

什么乱七八糟.明显是B.
走了6个小说后,我累垮了.had walked 自然是过去完成时,正因为有了这个完成动作,我才有后面的累垮.I was tired out完全是一句正常的过去时的句子 .After I had walked for six hours不过是个从句告诉你此条件发生了而已.
别被had吓唬掉了,它们老跟过去时一起蒙人~