A spanner is a（）.

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

单项选择题A ship must have a self-contained breathing apparatus to be used as protection from gas leaking from a refrigeration unit. To meet this requirement，you may use（）.

A.a gas mask certified by the Mine Safety and Health Administration
B.the same self-contained breathing apparatus required with the fireman's outfit
C.an oxygen breathing apparatus，provided that the device has been inspected within three years
D.a portable ventilation system that will provide a complete change of air every three minutes

单项选择题A ship helicopter landing deck on which fueling operations are conducted must have a fire protection system that is capable of discharging at 100 psi pressure a foam spray of at least（）.

A.30 gallons per minute
B.40 gallons per minute
C.50 gallons per minute
D.60 gallons per minute

单项选择题A portable foam (stored-pressure type) fire extinguisher would be most useful in combating a fire in（）.

A.generators
B.oil drums
C.the bridge controls
D.combustible metals

单项选择题A portable dry chemical fire extinguisher discharges by（）.

A.gravity when the extinguisher is turned upside down
B.pressure from a small CO₂ cartridge on the extinguisher
C.air pressure from the hand pump attached to the extinguisher
D.pressure from the reaction when water is mixed with the chemical