单项选择题
Halon extinguishes a fire by（）.
A.breaking the chain reaction B.smothering the fire C.cooling the fire D.coating the fuel with a nonflammable surface
单项选择题 Halon extinguishers used on a class C fire should be directed at the（）.
单项选择题 Good housekeeping on a vessel prevents fires by（）.
单项选择题 Generally，the first action in extinguishing an LFG fire caused by escaping gas is to（）.
