单选题In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decomposes and from （）Apetroleum crystalsBphosgene gasCwater vaporDcarbon monoxide
单选题
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
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