Which precaution should be taken when testing a line throwing gun?（）

单项选择题Which portable fire extinguisher should be used on a class C fire on board a vessel?（）

A.Carbon dioxide
B.Water (stored pressure)
C.Foam
D.Carbon tetrachloride

单项选择题Which portable fire extinguisher is normally recharged in a shore facility?（）

A.Dry chemical (cartridge-operated)
B.Water (cartridge-operated)
C.Water (pump tank)
D.Carbon dioxide

单项选择题Which item is NOT included in the fireman’s outfit on a cargo vessel?（）

A.Fire ax
B.Flashlight
C.rigid helmet
D.Fresh air breathing apparatus

单项选择题Which is a disadvantage of Halon as a fire extinguishing medium?（）

A.Conducts electricity
B.Difficult to store
C.Large volume necessary to be effective
D.Ineffective in powdered metal fires

单项选择题Which firefighting method is an example of an indirect attack on a fire?（）.

A.Bouncing a straight stream of water off the overhead to create spray effect
B.Spraying foam on a bulkhead and letting it flow down and over a pool of burning oil
C.Flooding a paint locker with CO₂ and sealing the compartment
D.Cooling adjacent bulkheads with water to prevent the spread of the fire by conduction