单项选择题
A.release B.absorb C.develop D.regenerate
What is the substance called which can readily be conve...
单项选择题What is the substance called which can readily be converted from a liquid into a vapor, and also from a vapor into liquid with a reasonably narrow range of pressure?（）
A.Refrigerator B.Refrigerant C.Cooling medium D.Brine
In a refrigeration plant the （） need defrosting.A.fanB....
单项选择题In a refrigeration plant the （） need defrosting.
A.fan B.compressor C.condenser D.evaporator
Hot gas defrosting uses the hot gas from （） to defrost ...
单项选择题Hot gas defrosting uses the hot gas from （） to defrost the evaporator.
A.starting air bottles B.diesel engines C.boilers D.refrigeration compressors
