赞题库-背景图
单项选择题

真空断路器的触头在哪个位置( )。

A.真空泡内
B.支撑绝缘子内
C.机构箱内
D.绝缘拉杆内
<上一题 目录 下一题>
热门试题

单项选择题会员收取客户的交易保证金必须( )交易所对会员收取的交易保证金比例。

A.低于
B.等于
C.高于
D.不高于

多项选择题Which conclusion concerning the pump working mechanism is correct?

A.the pump theoretical discharge rate depends on the diameter of piston, stroke length and stroke rate
B.the condition for valve ball falling down  is that the  uplift force decreases
C.The pressure inside the pump keeps stable at up and down stroke, and is not related with the submerge pressure
D.The pressure inside the pump at downstroke is related with the pump setting depth