____over and over again,but the old man still couldn`t understand.

题目

____over and over again,but the old man still couldn`t understand.
A.Having explained B.Having been explained C.Explained D.It had been explained
我选的是A,这不是一个完整的句子啊,中间无连词怎还用It的形式?

答案

首先 有but 就说明前后是两个句子 句子一定要有主语 选A没主语了.但是选A的话可以改成这样Having been explained over and over again,the old man still couldn`t understand.因为没but 前后可以共用一个主语 the o...