单项选择题
A.open-type B.hermetic C.A and B D.None of the above
In a compression refrigeration plant the refrigerant fl...
单项选择题In a compression refrigeration plant the refrigerant flows from the expansion valve and through the （） where it absorbs heat from the space being cooled and becomes a gas or vapor.
A.compressor B.condenser C.throttle valve D.evaporator
Since heat will not flow freely from a body at a （） tem...
单项选择题Since heat will not flow freely from a body at a （） temperature to another at a （） temperature, it is necessary to expend mechanical work, heat, or electrical energy from an external source to achieve refrigeration.
A.lower；higher B.shallower；deeper C.larger；smaller D.higher；lower
In the process of （）, liquid changes into gas.A.evapora...
单项选择题In the process of （）, liquid changes into gas.
A.evaporation B.frosting C.condensing D.compressing
