A.Point the horn down
B.Turn cylinder upside-down
C.Break the rupture disc
D.Pull pin，squeeze grip

A.is a finer，more diffuse water spray than low-velocity fog
B.requires that the water pressure be no greater than 60 psi
C.produces an effective fog pattern no more than 6 feet beyond the nozzle
D.extinguishes a fire by absorbing heat and reducing the supply of oxygen

A.at the top of the flames
B.at the base of the fire near the edge
C.in short quick bursts
D.toward the upwind side of the fire

A.Fires in electrical equipment
B.Flammable oils and greases
C.Class A fires in ordinary combustibles
D.Materials containing their own oxygen

A.cooling
B.smothering
C.shielding of radiant heat
D.breaking the chain reaction

A.breaking the chain reaction
B.smothering the fire
C.cooling the fire
D.coating the fuel with a nonflammable surface

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

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

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

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