—Youknowthatyouweredrivingat100kilometresperhour,don'ty...

问题详情：

—You know that you were driving at 100 kilometres per hour, don't you?

—No, officer, I ________have car can't do more than 80.

A．mustn't                  B．shouldn't

C．may not                 D．couldn't

【回答】

D　[couldn't have done是对过去的否定推测。]

知识点：情态动词

题型：选择题