He looks very tired . He to bed too late last night . A. must go B. must have goneC. coul

问题补充：

He looks very tired . He to bed too late last night .

A. must go

B. must have gone

C. could go

D. didn\t go

答案：

A. must go

B. must have gone

C. could go

D. didn\t go

解析：must 用于表示推测时，只能用于肯定句，完成式表示对过去情况的推测。