Question

He ___________ unwisely, but he was at least trying to do something helpful.

1. A.
   may have acted
2. B.
   must have acted
3. C.
   should have acted
4. D.
   would act

Answer 1

A
试题分析：句意：他的行为也许不明智，但是他至少能够尝试做一些有帮助的事了。may have done可能已经做了；must have done一定做过某事；should have done应该应经做过某事； would done过去将要做。根据句意故选A。
考点：考查情态动词的用法。
点评：本题难度适中。情态动词是高中阶段的重要的语法项目，需要考生掌握它们的不同的语法及区别，尤其是情态动词的完成式表示对过去的推测，不同的情态动词推测的可能性大小上不同，需要考生理解它们的不同的语法。
即学即练：Why didn’t you tell me there was no meeting today ? I _____ all the way here through the heavy snow.
A. needn’t have drive
B. can’t have driven
C. mustn’t have driven
D. shouldn’t have driven
解析：A。句意：你为什么不告诉我今天没有会？我本来没必要冒着大雪开车跑这么多路。Needn’t have done表示本来没必要。答案为A。