Question

 The light in his room is still on,  so he ________ to bed.

A. mustn’t have gone

B. must have gone

C. shouldn’t have gone

D. can’t have gone

Answer 1

【解析】选D。由他房间里的灯还亮着推测，他不可能已经上床睡觉了，应填can’t have gone 。must have done 表示对过去的肯定的推测，一般只用于肯定句；should have done表示“本应该做某事（而事实上并没有做）”。