题目

用测电笔可辨别火线与零线，如图所示的握笔方法正确的是( )A. B. C. D. 答案：【答案】A【解析】用测电笔来鉴别火线与零线时，笔尖接触要检测的导线，手接触笔尾金属体，才能在接触火线时氖管发光，接触零线时氖管不发光；要注意手一定不要与笔尖金属体接触．A正确，BCD正确。3.  She is very g__________ and she is never angry.