单项选择题
A.latent heat of fusion B.latent heat of vaporization C.specific heat of vaporization D.latent heat of the gas
The （） compressor and its electrical motor are entirely...
单项选择题The （） compressor and its electrical motor are entirely housed in a gas-tight casing.
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
