单项选择题
A.pressurestat B.high pressure cutout C.solenoid valve D.low pressure cutout switch
The pressure range between the system cut in and cut ou...
单项选择题The pressure range between the system cut in and cut out pressures in a refrigeration unit is known as（）
A.opposing operational drag B.pressure distribution C.differential D.system purge
A fluid coil will （）large quantities of heat when it ch...
单项选择题A fluid coil will （）large quantities of heat when it changes state from a liquid to a vapor.
A.release B.absorb C.develop D.regenerate
Refrigerant entering the compressor of a refrigeration ...
单项选择题Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）
A.Sub-cooled liquid B.Sub-cooled vapor C.Superheated vapor D.Liquid
