对无法进行直接验电的设备、高压直流输电设备和雨雪天气时的户外设备，可以进行间接验电。即通过设备的机械指示位置、电气指示、带电显示装置、仪表及各种遥测、遥信等信号的变化来判断。判断时，应有（）及以上的指示且所有指示均已同时发生对应变化，才能确认该设备已无电。若进行遥控操作，则应同时检查隔离开关（刀闸）的状态指示、遥测、遥信信号及带电显示装置的指示进行间接验电。
A、一个
B、两个
C、三个
参考答案：B
| 完形填空。 | |||
| It was seven o'clock on the morning of August 29th.The Kelly family were going to Brighton,a town by the sea. "Can we have breakfast 1 we leave?"asked Gina Kelly. "No,”said her mother. “We must leave now,or the traflic(交通)will be 2 . We'll have breakfast when we 3 the seaside. " Gina ran downstairs. “I’m ready,"she said. The family climbed into the 4 , and Dad started driving.In the front of the car was Mike. He was eleven. He didn’t talk but just 5 music. In the back of the car were Gina, her mother and Ellen. Gina was nine and Ellen was three. Dad drove very fast. “You’re driving too fast,"said Mum. “You don’t have to drive so fast.It’s 6.” Dad laughed and drove more slowly.There wasn’t 7 traffic , and they reached Brighton at nine o’clock. It was a sunny day, and the sea 8 very blue. "There’s a cafe,"said Gina. “Can we have breakfast there?" "Yes,” said Mum. They went into the cafe,and ate a very big breakfast. "Oh dear,I am full,"said Gina. “9 can I swim when I’ve got all that food inside me?” "Easy,"shouted Mike. “Just watch me!”He ran towards the sea,followed by Gina happily. What a(n) 10 day it was going to be! | |||
( )1. A. before | B. after | C. while | D. when |