单项选择题
The （）pump is usually used as the bilge feed pump to an oily water separator.
A.turbine B.screw C.vane D.ejector
单项选择题 The （）pump is usually used as the emergency bilge pump.
单项选择题 When starting a reciprocating pump, the inlet valve should be （）.
单项选择题 When starting a centrifugal pump, the discharge valve should be （）.
