单项选择题
A.air cooler B.economizer C.injector D.air blower
Oil water separators are used to ensure that ships don’...
单项选择题Oil water separators are used to ensure that ships don’t discharge oil when （） bilge water.
A.to pump off B.being pumped C.pumping out D.it pumping out
In general, （） is suitable for delivering small quantif...
单项选择题In general, （） is suitable for delivering small quantifies at high pressure.
A.reciprocating pump B.gear pump C.centrifugal pump D.vane pump
Under centrifugal pumps are the volute, diffuser, mixed...
单项选择题Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.
A.reciprocating B.hydraulic C.turbine D.vane
