单项选择题
A.promote refrigerant dehydration
B.be absorbed in the receiver
C.cause low condensing pressure
D.carry moisture and lead to corrosion
单项选择题 Air entering an air-cooled refrigeration system is indicated by （）.
单项选择题 When installing a hydraulic hose, which of the following precautions should be taken?（）
单项选择题 A lube oil filter can be used to remove most contaminants from lube oilA contaminant which will remain in the lube oil after filtering is （）.