must have done的反意疑问句问题

题目

must have done的反意疑问句问题
He must have finished his homework,hasn’t he
He must have finished his homework yesterday afternoon,didn’t he?
must have done本身就已经是对过去发生的是进行猜测了,为什么还有加不加yesterday afternoon的区别呢,为什么不加的就是强调现在的结果,而加的就是强调过去呢?

答案

答案应该是didn't he 一、对现在情况的推测,问句部分用主动词（do,be)一般现在时的适当形式.若是现在进行时,问句部分用现在进行时的适当形式表示.若是there be结构,问句用isn't/aren't there.如：1)He must be there...