A.opened and burned material removedB.left closed with ……

单项选择题After extinguishing a fire with CO2，it is advisable to（）.

A.use all CO₂ available to cool the surrounding area
B.stand by with water or other agents
C.thoroughly ventilate the space of CO₂
D.jettison all burning materials

单项选择题According to the regulations，what fire safety control feature is required in quick-closing shut off valves?（）

A.Electrical cut off switch
B.A fusible link
C.Manual cut off switch
D.A water spray actuator

单项选择题A vessel is constructed with a steel hull and an aluminum superstructure. Which statement is TRUE?（）

A.The aluminum will provide greater resistance to the spread of fire by conduction
B.The aluminum structure is usually attached to a steel coaming by a method that insulates the two metals
C.If the superstructure is stressed，an aluminum structure requires additional expansion joints to prevent fracture
D.The steel at the area of the aluminum-to-steel connection must be closely checked for galvanic corrosion

单项选择题A squeeze-grip type carbon dioxide portable fire extinguisher has been partially discharged. It should be（）.

A.labeled empty and recharged as soon as possible
B.replaced in its proper location if weight loss is no more than 25%
C.replaced in its proper location regardless of weight
D.replaced in its proper location if weight loss is no more than 15%

单项选择题A spring line is（）.

A.any wire rope used for mooring
B.a fire-warp
C.a mooring line running diagonally to the keel
D.a mooring line perpendicular to the keel