Question

If Harry did not attend the conference last night, he ________ too much work to do．

[　　]

A．

had to have had

B．

had had

C．

must have had

D．

must have

Answer 1

答案：C
解析：

注意条件句中的时态是did not attend，所以判断这不是叙述过去情况的虚拟语气。空格处是对过去情况的猜测——他一定昨天晚上有很多工作要做，所以才没有去参加会议的。