_____scores of times,but he still couldn't understand it.A.Having explainedB.Having been explainedC.Though it was explainedD.It was explained为什么不选B呢?
问题描述：
_____scores of times,but he still couldn't understand it.
A.Having explained
B.Having been explained
C.Though it was explained
D.It was explained
为什么不选B呢?
答
意思不通
答
have been explained貌似是被动的啊 解释的话你是主动方，你解释给他听，要选A。 C的话是though 和but不能同时出现，D项it指代不明，主谓宾混用了。
答
D
因为后面用了but,所以前面的句子一定要是一个独立的句子,只有D是一个独立的句子.