单项选择题
In the condenser, the hot, high pressure refrigerant gas is cooled by the sea water and becomes（）.
A.fresh water B.vapor C.mixture D.liquid
单项选择题 The boiling and condensation points of a refrigerant depend on the （） exerted upon it.
单项选择题 Faulty operation of any system is indicated by very definite （）.
单项选择题 The refrigerating agent can （） at low temperature in the evaporator.
