___many times,he finally understood it.A、He is told B、Having been told 选哪一个?

问题描述:

___many times,he finally understood it.A、He is told B、Having been told 选哪一个?
为什么

b.因为英语中不允许两个主句并列在一起(在一个句子中)而两者之间没有任何连词或其他主从关系.a 恰好犯了这样的错误.