电动机的绝缘电阻不小于（）时才可以使用
A．0.5MΩ
B．1MΩ
C．2MΩ
D．3MΩ
参考答案：A
_______________ while writing, he locked himself in his study.
A．Not to interrupt
B．Not being interrupted
C．Not to be interrupted
D．Being not interrupted
