单选题 I didn't see her in the meeting room this morning. She ______ at the meeting.

【正确答案】 D
【答案解析】虚拟语气。must表示推测时不用于否定句；shouldn't have done sth．表示“本不应谊做某事而实际上做了”； needn't have done sth．表示“本来不必做某事而实际上做了”；couldn't have done sth．表示“不可能做过某事”。