电气控制线路的表示方法有电气原理图、安装接线图和电器布置图三种。
参考答案:对
下列路由协议中,支持无类域间路由选择的有()。
A.OSPF
B.RIPv1
C.BGP
D.IGRP
Throughout history, the language________ by a powerful group spreads across a civilization. [ ]
A. speaking
B. spoken
C. to speak
D. to be spoken