On a ship，a fire drill shall be conducted once every（）.

单项选择题On a ship，a cabinet or space containing the controls or valves for the fixed firefighting system must be（）.

A.posted with instructions on the operation of the system
B.ventilated and equipped with explosion-proof switches
C.painted with red and black diagonal stripes
D.equipped with a battery powered source of emergency lighting

单项选择题On a class B fire，which portable fire extinguisher would be the LEAST desirable?（）

A.Carbon dioxide
B.Water (stored pressure)
C.Dry chemical
D.Foam

单项选择题Oily rags stored in a pile that is open to the atmosphere are a hazard because they may（）.

A.deteriorate and give off noxious gasses
B.spontaneously heat and catch fire
C.attract lice and other vermin and serve as a breeding ground
D.None of the above

单项选择题Normally，potable water systems are connected directly to the（）.

A.fire-main system
B.feed-water system
C.freshwater sanitary system
D.domestic water tank

单项选择题Line throwing apparatus aboard ship must contain（）.

A.two rockets，one of which shall be the buoyant type
B.three rockets，one of which shall be the buoyant type
C.four rockets，two of which shall be the buoyant type
D.five rockets，two of which shall be the buoyant type