What is the most important characteristic of the extinguishing agent in fighting a class C fire?（）

单项选择题What is required in addition to the heat，fuel，and oxygen of the fire triangle to have a fire?（）

A.Electricity
B.Chain reaction
C.Pressure
D.Smoke

单项选择题What is NOT listed on the metallic name plate required to be attached to hand portable fire extinguishers?（）

A.The rated capacity in gallons，quarts，or pounds
B.The hydrostatic test date of the cylinder
C.The name of the item
D.An identifying mark of the actual manufacturer

单项选择题What is NOT a characteristic of carbon dioxide fire-extinguishing agents?（）

A.Effective even if ventilation is not shut down
B.Will not deteriorate in storage
C.Non-corrosive
D.Effective on electrical equipment

单项选择题What is meant by the term overhaul in firefighting?（）

A.Slow down the spread of fire by cooling adjacent structures
B.Cover the fire with foam
C.Smother the fire with a blanket or similar object
D.Break up solid objects to ensure that any deep seated fires are extinguished

单项选择题What is best suited for fighting a fire in a ballast control room?（）

A.Automatic sprinkler system
B.Steam smothering system
C.Dry chemical system
D.Carbon dioxide system