___________ had enough time,they would have visited the Great Wall.A) Had they B) Have they C) Would they have D) If the

问题描述:

___________ had enough time,they would have visited the Great Wall.A) Had they B) Have they C) Would they have D) If they

答案是A
这是虚拟语气的句子.Had they had enough time=== if they had had enough time --------这是对已经过去的事情的虚拟/ 假设.
== They didn't visit the Great Wall because they DIDN'T have enough time.时态前后一致吗??可以用have they 吗?1 have they ------不可以用,因为关注的是以前的事情。2 时态前后必须一致:had had 搭配would have visited