问题
选择题
He _______ the best person you had been expecting for the job, but who else _______?
A．may not be; could be
B．couldn’t be; might be
C．might not have been; could have been
D．mustn’t be; must have been
答案
答案：C
题目分析：句意：他可能不是你过去所期望的胜任这个工作最好的人，但是还有谁可能是呢？might not have been过去可能没有做某事，could have been过去能够做某事，根据句意，故选C.
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;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