用测电笔检测单相插座,如果两相都不显示,属于()
A.正常
B.断路
C.缺相
D.漏电
参考答案:C
The Central Limit Theorem states that, for any distribution, as n gets larger, the sampling distribution:()
A. becomes larger.
B. becomes smaller.
C. approaches a normal distribution.
加强避雷线运行维护工作,定期打开()检查,保证避雷线与杆塔接地点可靠连接。