单项选择题
A.motor overload would open B.relief valve would open C.pump would eventually overheat D.motor would overheat
In order to accurately measure very low pressures, whic...
单项选择题In order to accurately measure very low pressures, which of the instruments listed should be used?（）
A.Compound gage B.Bonrdon tube C.Manometer D.Deadweight gage
Reduced capacity, accompanied by vibration and noise at...
单项选择题Reduced capacity, accompanied by vibration and noise at the suction of a centrifugal pump is a result of （）.
A.cavitation B.water hammer C.fluid friction D.steam knock
The refrigerant leaves the evaporator of a refrigeratio...
单项选择题The refrigerant leaves the evaporator of a refrigeration system as a low pressure （）.
A.sub-cooled liquid B.high temperature liquid C.oil saturated liquid D.superheated vapor
