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

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

单项选择题A spanner is a（）.

A.cross connection line between two main fire lines
B.special wrench for tightening couplings in a fire hose line
C.tackle rigged to support a fire hose
D.None of the above

单项选择题A small fuel spillage has occurred during helicopter refueling. After the leak has been stopped and fire-control personnel have been notified and are standing by，the next step is to（）.

A.proceed with fueling operation
B.have helicopter move to a safer location
C.wash spilled fuel away with a flood of water
D.clean spilled fuel with rags