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

A . increases the size of foam bubbles formed B . increases the rate of foam production C . improves the extinguishing properties of foam D . gives the nozzleman more freedom of movement，since it can be placed anywhere in the hose line

A . refrigerant boiling out of solution from the lube oil B . liquid refrigerant flooding the compressor and system C . lube oil viscosity being reduced by refrigerant dilution D . compressor suction pressure suddenly increasing

A . mattress fires B . oil fires C . wood fires D . All of the above

A . solid materials such as wood or bales of fiber B . flammable liquids C . electrical equipment D . metallic solid

A . generators B . oil drums C . the bridge controls D . combustible metal

A . solid materials such as wood or bales of fiber B . inflammable liquids C . electrical equipment D . metallic solid

A . overheated compressor bearings B . excess lube oil viscosity C . carbon deposits on the compressor piston rings D . wax crystals forming in the lubricant

A . shutting off the air supply B . cooling the fuel to below ignition temperature C . dispersing the fuel D . removing the source of ignitio

A . expansion valve to overfeed B . compressor to knock C . water regulating valve to fail D . crankcase drains to plug

A . put back in service if some CO remains B . hydrostatically tested C . retagged D . recharged

A . reading the gage pressure B . weighing the extinguisher C . discharging a small amount of CO D . seeing if the seal has been broke

A . put out B . put on C . take off D . take i

A . turning it upside down B . pressing the foam lever C . squeezing the grip handle D . opening the hose valve

A . soild materials such as wood or bales of fiber B . flammable liquids C . a piece of electrical equipment D . combustible metallic solid

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

A . reading the gage pressure B . weighing the extinguisher C . discharging a small amount of CO D . seeing if the seal has been broke

A . it provides cooling as a secondary effect B . works well on extinguishing electrical fires C . can be used to combat combustible metal fires D . All of the above

A . cooling B . chemical action C . smothering D . inerting the air

A . put back in service if some C0 remains B . hydrostatically tested C . retagged D . recharged

A . generators B . oil drums C . the bridge controls D . combustible metal

A . excessively high oil temperatures B . water or moisture contamination C . fuel dilution D . life its cylinder relief vale

B、电池供电