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單項(xiàng)選擇題

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

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單項(xiàng)選擇題

In general, （） is suitable for delivering small quantifies at high pressure.

A.reciprocating pump
B.gear pump
C.centrifugal pump
D.vane pump

單項(xiàng)選擇題

Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.

A.reciprocating
B.hydraulic
C.turbine
D.vane

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