开拓掘进率
参考答案:开拓巷道掘进总进尺/(矿井产量+工程出煤)(m/万t)
The students in our school have ________ days off and spend _________ time doing their homework.
A.less; less
B.less; fewer
C.more; less
D.more; fewer
火力发电厂中,下列哪几种接线在发电厂与变压器之间宜装设断路器和隔离开关?()
A.两台50MW发电机与一台双绕组变压器作扩大单元连接
B.110MW发电机与自耦变压器为单元连接
C.125MW发电机与三绕组变压器为单元连接
D.200MW发电机与双绕组变压器为单元连接