The room is in a terrible mess; it _____ have been cleaned. [ ]

A. can't

B. mustn't

C. shouldn't

D. wouldn't

下列句子语言表达得体的一项是[ ]

A．会议开始前，主持人特别提醒：“为了保持会场安静，请各位关闭手机，否则后果自负！”

B．有人从公交车上往外扔香蕉皮．一位乘客冲着他说：“老兄，你太过分了！积点德吧!

C．酒店经理对员工们说：“大家要用心做好服务工作，让客人有宾至如归的感觉。”

D．提到自己的父亲，老刘动情地说：“令尊经常告诫我们，做人要清清白白。”