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问题详情

All the mobile phones must______ before the meeting starts.

A、be turning off

B、turn off

C、be turn off

D、be turned off

时间：2021-09-01 16:22 关键词：安徽教育在线安徽广播电视大学土木工程

答案解析

D

相关问题

A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
— — I mean the best way is using your own mobile phone or computer to operate it.
A cabinet or space containing the controls or valves for the fixed firefighting system must be（）.
A cabinet or space containing the controls or valves for the fixed firefighting system must be（）.
All the mobile phones must______ before the meeting starts.