检修的安全距离，低压操作中，人体或所携带的工具与带电体之间的距离不小于（）。
A、0.1m
B、0.2m
C、0.3m
D、0.4m
参考答案：A
— Are they about to have dinner?
— Yes, it____ in the dining room.
[ ]
A. is being served
B. is served
C. is serving
D. serves
交流接触器型号为CJ12—150中“150”表示的意义是（）。
A.主触点额定电流
B.接触器额定功率
C.设计序号
D.接触器额定电压
