单项选择题
Centrifugal pumps, however, can be designed with a number of impellers （） to attain a large amount of liquid.
A.in series
B.in parallel
C.assembled
D.together
点击查看答案&解析
相关考题
-
单项选择题
Sealing in pump shaft is achieved by means of the （）.
A.gasket
B.packing
C.washer
D.spring -
单项选择题
（） is the breakdown of surface tension between oil droplets in an oil water mixture which causes them to join and increase in size.
A.Wear
B.Contaminating
C.Coalescence
D.Coarse separating -
单项选择题
Centrifugal pumps are popular because they are very simple in construction,and produce smooth, constant, （） discharge.
A.non-pulsating
B.pulsating
C.positive
D.non-positive
