—Tom graduated from college at a very young age.—Oh,he__________have been a very

题型：不详难度：来源：

—Tom graduated from college at a very young age.
—Oh,he__________have been a very smart boy then.

A．could

B．should

C．might

D．must

答案

D

解析

试题分析：考察情态动词用法。Could have done本可以做某事，实际上却未做；should have done本应该做某事，实际上却为做；might have done也许做了某事；must have done一定做了某事；句意：—Tom很小的时候就大学毕业了。—啊！他一定是一个很聪明的学生。根据句意说明D正确。
点评：本题是高考必考考点，一定要牢记句型意思。must have done过去肯定做了某事。should have done 本应该做而实际未做。 can’t have done 过去不可能做了某事；shouldn’t have done 本不应该做而实际做了。 need have done 本有必要做某事；needn’t have done 本没有必要做某事；注意没有 mustn’t have done的形式。