A.coolingB.smotheringC.shielding of radiant heatD.break……

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（）.

A.base of the equipment
B.top of the equipment
C.power source
D.source of the fire

单项选择题Good housekeeping on a vessel prevents fires by（）.

A.allowing better access in an emergency
B.eliminating potential fuel sources
C.eliminating trip hazards
D.improving personnel qualifications

单项选择题Generally，the first action in extinguishing an LFG fire caused by escaping gas is to（）.

A.sweep flames away with water spray
B.shut off the leak
C.use a chemical foam fire extinguisher
D.call the local fire department

单项选择题Gas masks（）.

A.should be worn while fighting a fire
B.can be used in atmospheres deficient in oxygen
C.filter contaminants from air that is to be breathed
D.may be substituted for a self-contained breathing apparatus