CA6140型卧式车床主轴正转有（）级，其中高速（）级，中低速有（）级。
参考答案：24；6；18
The boy has _______ questions to ask his teacher in every class.
A．too much
B．too many
C．much too
D．many too
BKD-630/1140（660）智能型矿用隔爆型真空馈电开关，具有哪些保护？用来控制哪些电气设备？
