问题补充:
He the test, but he wasn’t careful enough.
A. was able to pass
B. must have passed
C. could have passed
D. might be able to pass
答案:
A. was able to pass
B. must have passed
(答案→)C. could have passed
D. might be able to pass
解析:考查虚拟语气。句意:他本来能够通过考试,但是他不够细心。“would+have+done”表示对过去事情的假设,表示本来会做而没有做的动作。联系句子意思可知选C。