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

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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

单项选择题A passenger vessel is required to have a supervised patrol when（）.

A.there are passengers berthed on board
B.navigating in excess of eight hours
C.the vessel has substantial wood in its construction
D.there is no automatic fire-detection system installed

单项选择题A marine chemist issues gas free certificates and is certified by the（）.

A.Mine Safety Appliance Association
B.American Chemical Society
C.Marine Chemists Association
D.National Fire Protection Association