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單項(xiàng)選擇題

Before charging a refrigeration unit, the refrigerant charging lines should be（）

A.flushed with clean refrigerant oil
B.purged with the refrigerant
C.washed with an ammonia and alcohol solution
D.grounded to compressor

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單項(xiàng)選擇題

In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decomposes and from （）

A.petroleum crystals
B.phosgene gas
C.water vapor
D.carbon monoxide

單項(xiàng)選擇題

In an operating refrigeration system low on refrigerant, a liquid line sight glass will（）

A.be clear
B.be blue
C.be light green
D.show bubbles

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