单项选择题
The function of （） in a refrigeration plant using Freon is to move moisture from all refrigeration system.
A.filter B.filter drier C.heat exchanger D.air cooler
单项选择题 The boiling and condensation points of refrigerant mainly depend on the （） exerted upon it.
单项选择题 In a compression refrigeration plant the refrigerant is under low pressure in the （） and under high pressure in the （）.
单项选择题 A feeler or thermal bulb is used for the expansion valve to （）.
