Dry chemical fire extinguishers are effective on which type(s) of fire?（）

单项选择题Dry chemical extinguishers extinguish class B fires to the greatest extent by（）.

A.cooling
B.smothering
C.oxygen dilution
D.breaking the chain reaction

单项选择题Convection spreads a fire by（）.

A.heated gases flowing through ventilation systems
B.the transfer of heat across an unobstructed space
C.burning liquids flowing into another space
D.transmitting the heat of a fire through the ship's metal

单项选择题Controls for a fixed carbon dioxide system shall be mounted（）.

A.directly outside the space protected by the system
B.as near the gas cylinders as possible
C.in the pilothouse
D.on the main deck near the bow

单项选择题Control of flooding should be addressed（）.

A.first
B.following control of fire
C.following restoration of vital services
D.only if a threat exists

单项选择题Control of fire on a ship should be addressed（）.

A.immediately after restoring vital services
B.immediately
C.following control of flooding
D.following establishment of fire boundaries