单项选择题
A.propeller B.impeller C.circumference D.screw
The pressure head of a pump is given in the unit of （）....
单项选择题The pressure head of a pump is given in the unit of （）.
A.kg B.MPa C.meter fluid column D.None of the above is true
A gear pump belongs to （） according to its working prin...
单项选择题A gear pump belongs to （） according to its working principle.
A.reciprocating pumps B.positive displacement pumps C.centrifugal pumps D.centripetal pumps
Gear pumps are of positive displacement type pumps beca...
单项选择题Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.
A.depending on B.in relative to C.regardless of D.because of
