Look! Tom is too sleepy to work．He up watching TV．
A. mustn’t have stayed
B. shouldn’t have stayed
C. mustn’t stay
D. ought not to say．
网友回答
A. mustn’t have stayed
(答案→)B. shouldn’t have stayed
C. mustn’t stay
D. ought not to say．
解析：
从上句Look! Tom is too sleepy to work．说明他本不该熬夜看电视，而实际上是熬夜导致太困了。shouldn’t have done是“本不该做…而实际上却做了”。