单选题A multistage centrifugal pump can be BEST described as having （）.Atwo or more impellers housed together in one casing and mounted on a single shaftBa single stepped impeller mounted in a progressively staged casingCa large radial clearance between the impeller and casing to prevent overheating due toDan increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stages
单选题
A multistage centrifugal pump can be BEST described as having （）.
A
two or more impellers housed together in one casing and mounted on a single shaft
B
a single stepped impeller mounted in a progressively staged casing
C
a large radial clearance between the impeller and casing to prevent overheating due to
D
an increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stages
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