题目内容
Attention, please! All the mobile phones ______ during the meeting.
A. must keep off B. have kept off C. are keeping off D. must be kept off
试题答案
1、D
相关题目
Attention, please! All the mobile phones ______ during the meeting.
A. must keep off B. have kept off C. are keeping off D. must be kept off
查看习题详情和答案>>