单项选择题
A.expand B.evaporate C.condense D.distil
Because the expansion valve is just （） way open, the re...
单项选择题Because the expansion valve is just （） way open, the refrigerant is under low pressure in the evaporator.
A.little B.few C.a little D.a few
As the refrigerant passes through the valve orifice, it...
单项选择题As the refrigerant passes through the valve orifice, its pressure is reduced and part of the refrigerant turns into （）.
A.liquid B.oily mixture C.emulsion D.vapor
Freon 12 which is used to produce intense cold is norma...
单项选择题Freon 12 which is used to produce intense cold is normally a （） when at atmospheric pressure and temperature.
A.liquid B.gas C.solid D.water only
