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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

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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

單項(xiàng)選擇題

Domestic water pump is started automatically by （） which operates as the water level falls to a predetermined level.

A.a level controller
B.a temperature switch
C.a pressure switch
D.a floating ball

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