Tom’s score on the test is the highest in the class. He .
A. should study last night
B. should have studied last night
C. must have studied last night
D. must study last night
网友回答
A. should study last night
B. should have studied last night
(答案→)C. must have studied last night
D. must study last night
解析：句意：汤姆的考试成绩是班级最高的，他昨晚一定是学习了。因为是对昨晚事情的推测，所以用情态动词+have done，排除AD，should have done本应该做却没有做，must have done过去一定做了，符合句意，所以选C。