用作高电压保护装置的避雷器应安装在酚醛纤维塑料防爆接线箱内,安装前、后及()应作定期检测。
A.雷雨前
B.雷雨后
C.冰冻前
D.冰冻后
参考答案:B
用作高电压保护装置的避雷器应安装在酚醛纤维塑料防爆接线箱内,安装前、后及()应作定期检测。
A.雷雨前
B.雷雨后
C.冰冻前
D.冰冻后
参考答案:B
完形填空。 | ||||
Mr. Evans lived in a city. He was a maths _1_ three years ago. He taught well and his students _2_ | ||||
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