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單項(xiàng)選擇題

Through a （） pump, the liquid is transferred from the suction to the discharge by the mechanical variation of the volume of a chamber or chambers.

A.positive displacement
B.ejector
C.centrifugal
D.air compressor

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單項(xiàng)選擇題

In a （） the center screw is driven and the outer screws idle.

A.single screw pump
B.double-screw pump
C.triple screw pump
D.centripetal pump

單項(xiàng)選擇題

The discharge flow of a reciprocating pump is （）.

A.steady
B.in pulsation
C.continuous
D.large

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