( )是防止发生直接触电和电气短路的基本措施。
A.接地
B.接零
C.绝缘
D.中性点直接接地
参考答案:C
解析:绝缘是防止发生直接触电和电气短路的基本措施。
He couldn't _________an answer when I asked him why he was late.
A.come over
B.cat up with
C.come out
D.come up with
不准携带笨重工具和()登高作业。