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單項(xiàng)選擇題

The amount of fluid delivered by a centrifugal pump can be regulated by （）.

A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is tree

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單項(xiàng)選擇題

While flowing through the volute in a centrifugal pump, part of the （） energy of the liquid is converted to （） energy.

A.kinetic；pressure
B.kinetic；essential
C.pressure；kinetic
D.pressure；height

單項(xiàng)選擇題

The amount of fluid delivered by a screw pump can be regulated by （）.

A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is tree