单项选择题
A.depending on B.in relative to C.regardless of D.because of
The gear and screw pumps are classified as （）.A.variabl...
单项选择题The gear and screw pumps are classified as （）.
A.variable stroke pumps B.multistage pumps C.positive displacement pumps D.triple-ported pumps
Through a （） pump, the liquid is transferred from the s...
单项选择题Through a （） pump, the liquid is transferred from the suction to the discharge by the mechanical variation of the volume of a chamber or chambers.
A.positive displacement B.ejector C.centrifugal D.air compressor
A vane pump belongs to （） according to its working prin...
单项选择题A vane pump belongs to （） according to its working principle.
A.reciprocating pump B.positive displacement pump C.centrifugal pump D.centripetal pump
