变电站使用的电压互感器一般用于哪些保护？
参考答案：
距离保护、高频保护、低频保护、方向保护、低电压减载、低电压闭锁、自投装置、同期重合闸。
施工总承包合同协议书中应包括( )。
A．施工工期
B．质量检验
C．安全施工
D．质量标准
Why are the private lands surrounding Glacier National Park so important
A．They function as a hunting preserve.
B．They are restricted to government use.
C．They are heavily populated.
D．They contain natural habitats of threatened species.
