单项选择题
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
A.a low load on the unit B.a clogged pump suction strainer C.a blockage in the line between the pump and hydraulic motor D.the hydraulic motor turning too fast
单项选择题 A salinity indicator is used to determine the （）.
单项选择题 If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
单项选择题 If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
