单项选择题
A.lowest absolute humidity
B.lowest relative humidity
C.highest absolute humidity
D.highest relative humidity
单项选择题 If you find an extremely large refrigerant leak while using a halide torch, your flame will（）
单项选择题 Before charging a refrigeration unit, the refrigerant charging lines should be（）
单项选择题 In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decomposes and from （）