单项选择题
A.Closing of the solenoid valve B.Closing of the expansion valve C.An increase in the suction pressure D.Decreasing the suction pressure
In an electro-hydraulic steering gear system, when will...
单项选择题In an electro-hydraulic steering gear system, when will the variable displacement pump be placed on stroke?（）
A.When the helm is at any angle other than amidships B.When the six-way valve is opened C.When the ram relief valves lift D.When the redder angle is different from the position of the helm
An additive used to improve the ability of a lube oil t...
单项选择题An additive used to improve the ability of a lube oil to reduce friction is known as a/an （）.
A.suppressant additive B.dispersant additive C.extreme pressure additive D.viscosity improver additive
The suction - force principle of operation is a typical...
单项选择题The suction - force principle of operation is a typical characteristic of （）.
A.centrifugal pumps B.jet pumps C.propeller pumps D.reciprocating pumps
