Question

【题目】The student on duty are supposed to _________ the chalk _________ the blackboard before class.

A. clean…off B. clean...up C. clean…out D. clean…away

Answer 1

【答案】A

【解析】试题分析：句意：值日的学生应该在上课前把黑板上的粉笔字擦干净。擦干净，擦掉用clean---off。故选A。