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单选题
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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Piston pumpB
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CopperB
Copper and carbonC
CarbonD
Bronze
考题
单选题Centrifugal pumps, however, can be designed with a number of impellers （） to attain a large amount of liquid.A
in seriesB
in parallelC
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考题
单选题Which of the devices listed is common to all types of pumps?（）A
A power end and fluid endB
A propeller and educatorC
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A turbine and piston
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单选题The volute of centrifugal pump also acts as a diffuser converting （）into pressure head.A
mechanical energyB
heat energyC
potential energyD
kinetic head
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