问题
选择题
------I don’t know why he has made such a silly mistake in the exam.
------ He ____________ it before he handed in the paper.
A．may have checked
B．might check
C．must have checked
D．should have checked
答案
答案：D
考查情态动词+have done的用法：A. may have checked可能已经检查了，B. might check 可能检查了， C. must have checked一定检查了，D. should have checked 本该检查而没有，句意是：--我不知道为什么他在考试中犯了这么愚蠢的错。--他本该交试卷钱检查一下的。选D。