The wooden plug inserted in the vent of a damaged tank of a ship should be removed in case it is decided to（）.

单项选择题The ventilation system of your ship has fire dampers restrained by fusible links. Which statement is TRUE?（）

A.A fusible link will automatically open after a fire is extinguished and reset the damper
B.Fusible links must be replaced at every inspection for certification
C.Fusible links are tested by applying a source of heat to them
D.Fusible links must be replaced if a damper is activated

单项选择题The type of extinguisher which should be used for an electricity fire is（）.

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

单项选择题The supply of carbon dioxide used in the fixed extinguishing system aboard a cargo vessel MUST be at least sufficient for（）.

A.all the spaces of a vessel
B.all cargo spaces
C.the engine room and largest cargo space
D.the space requiring the largest amount

单项选择题The success of an indirect attack on a fire depends on the（）.

A.size of the fire when initially observed
B.complete containment of the fire
C.cooling ability of the firefighting agent
D.class of the fire

单项选择题The straight stream capability of an all-purpose nozzle is used in fighting a class A fire to（）.

A.shield fire fighters from radiant heat
B.break up burning material
C.get the most water possible on the fire
D.drive heat and smoke ahead of the fire fighters