问题补充：
--- Mum, I am feeling tired and sleepy now.
--- You so late last night.
A. couldn’t have stayed up
B. mustn’t have stayed up
C. shouldn’t have stayed up
D. needn’t have stayed up
答案：
A. couldn’t have stayed up
B. mustn’t have stayed up
(答案→)C. shouldn’t have stayed up
D. needn’t have stayed up
解析：可联系答.案.网客服索取。
