高压电压互感器二次侧要有一点接地，金属外壳也要接地。
参考答案：对
击实试验中，最后一层超出筒顶越高，试件所受的击实功越大，也就越密实。
____ the Internet is bridging the distance between people, it may also be breaking some families or
will cause other family problems.[ ]
A. When
B. If
C. While
D. Since
