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.

In the process of （）, liquid changes into gas.A.evapora...

单项选择题In the process of （）, liquid changes into gas.

If the capacity of the refrigeration compressor is too ...

单项选择题If the capacity of the refrigeration compressor is too large, the saturation temperature will （）.

If the capacity of the refrigeration compressor is too ...

单项选择题If the capacity of the refrigeration compressor is too small, the excess vapor will accumulate in the evaporator, causing the pressure to （）.