单选题A foam-type portable fire extinguisher would be most useful in combating a fire in（）.A solid materials such as wood or bales of fiberB flammable liquidsC a piece of electrical equipmentD combustible metallic solids

A foam-type portable fire extinguisher would be most useful in combating a fire in ______.

A.solid materials such as wood or bales of fiber

B.flammable liquids

C.a piece of electrical equipment

D.combustible metallic solid

A portable foam (stored-pressure type) fire extinguisher would be most useful in combating a fire in ______.

A.generators

B.oil drums

C.the bridge controls

D.combustible metals

The most effective way of applying carbon dioxide from a portable extinguisher to a fire is by ______．

A.Forming a cloud cover over the flames

B.Directing the gas at the base of the flames in a slow sweeping motion

C.Discharging the carbon dioxide into the heart of the flames

D.Bouncing the discharge off an adjacent bulkhead just above the burning surface

Foam-type portable fire extinguishers are most useful in combating fires involving ______.

A.solid materials such as wood or bales of fiber

B.inflammable liquids

C.electrical equipment

D.metallic solids

A portable dry chemical fire extinguisher discharges by ______.

A.gravity when the extinguisher is turned upside down

B.pressure from a small CO2 cartridge on the extinguisher

C.air pressure from the hand pump attached to the extinguisher

D.pressure from the reaction when water is mixed with the chemical

An ABC dry chemical fire extinguisher would be LEAST effective against a fire in ______.

A.a mattress

B.spilled liquids such as oil or paint

C.high voltage electrical gear

D.a trash can

A foam-type portable fire extinguisher is most useful in fighting a fire in ______.

A.generators

B.oil drums

C.the bridge controls

D.combustible metals

How do you operate a portable CO2 fire extinguisher?______.

A.Point the horn down

B.Turn cylinder upside-down

C.Break the rupture disc

D.Pull pin, squeeze grip