--Why are your eyes so red? You have slept well last night.---Yeah I stayed up late writ

问题补充：

--Why are your eyes so red? You have slept well last night.---Yeah, I stayed up late writing a report.

A. can

B. mustn

C. needn

D. won

答案：

(答案→)A. can

B. mustn

C. needn

D. won

解析：句意：你眼睛怎么这么红？你昨晚一定没睡好吧。---我熬夜写报告。根据why are your eyes so red？可以得出对方一定没有睡好，故用can’t（不可能）。Mustn’t（禁止，不准）；needn’t（不必）；won’t（不会）。

【考点定位】考察情态动词推测用法。