The fire extinguishing action of CO2 comes mostly from （）.

A . Foam B . Carbon dioxide C . Dry chemical D . Water fog

A . Carbon dioxide is corrosive when exposed to fire B . Carbon dioxide should be applied slowly to a large engine room fire C . Its total cooling effect is far greater than water D . Its smothering effect is excellent for class B fire

A . opened and burned material removed B . left closed with vents off until all boundaries are cool C . checked for oxygen content D . doused with water to prevent reflash

A . Dry chemical B . Halon C . Low velocity fog D . Steam

A . the "snow" which is sometimes discharged along with the gas is toxic B . prolonged exposure to high concentrations of C0 gas causes suffocation C . rapid dissipation of the C0 vapor D . the C0 gas is lighter than air and a large amount is required to extinguisha fire near the deck

A . invert the CO extinguisher B . squeeze the two trigger handles together C . remove the locking pin D . open the discharge valve

A . painted red and labeled B . concealed from the crew C . protected by plexiglass D . padlocked

A . flashing point B . combustion point C . auto-ignition point D . lower explosive limit

A . Check the tag to see when the extinguisher was last charged B . Release a small amount of CO ; if the CO discharges，the extinguisher is acceptable C . Weigh the extinguisher and compare the weight against that stamped on the valve D . Recharge the extinguisher at least once each year

A . maximum pressure allowed at that branch B . name of the space or spaces which it serves C . date of the last maintenance inspection D . pressure needed to maintain an effective stream at that point

A . Dry chemical B . Foam C . Water D . Carbon dioxide

A . cooling B . smothering C . oxygen dilution D . breaking the chain reactio

A . dry chemical or foam B . foam or soda acid C . carbon dioxide or foam D . carbon dioxide or dry chemical

A . at the base of the flames B . at the center of the flames C . to the lee side of the flames D . over the tops of the flame

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

A . smoke density has been decreased sufficiently to see the bulkhead opposite the compartments entrance B . a lifeline and explosion proof flash light are used C . all smoke and toxic fumes are removed and an adequate oxygen supply is present D . overhaul has been completed to remove any possible source of re-ignitio

A . air from contacting the oil vapors B . permitting re-ignition boiling of the heated oil C . spontaneous combustion below the oil surface D . toxic fumes from escaping to the surface

A . water B . foam C . the range hood extinguishing system D . fire damper

A . Soda acid B . Carbon dioxide C . Dry chemical D . Cartridge-operated Foam

A . Class "A" and class "B" B . Class "B" and class "C" C . Class "A" and class " C" D . Class "C", class "D", and class "E&quot

A . Alcohol foam B . Dry chemical C . Chemical foam D . Water fog

A . class A B . class B C . class C D . class D

A.CO2 B.ABC dry chemical C.CO2 propelled foam D.All of the above

A.foam B.water C.dry powder