A.stop ventilationB.stop the vesselC.de-energize the ci……

单项选择题An extinguishing agent which effectively cools，dilutes combustible vapors，removes oxygen，and provides a heat and smoke screen is（）.

A.carbon dioxide
B.Halon 1301
C.dry chemical
D.water fog

单项选择题An engine compartment gasoline fire requires which type of extinguisher?（）.

A.Carbon dioxide
B.Dry chemical
C.Foam
D.All of the above

单项选择题An effective method for moving patients with spinal injuries onto a spine board is known as the（）.

A.pack-strap carry
B.two man extremities carry
C.fireman's drag
D.four man log roll

单项选择题An aircraft has indicated that he wants you to change course and follow him. You cannot comply because of an emergency on board. Which signal should you make?（）

A.Fire a red flare at night or a red smoke signal by day
B.Send the Morse signal N by flashing light
C.Make a round turn (360°) and resume course
D.Make an S turn (hard right then hard left) and resume course

单项选择题An advantage of a dry chemical over a carbon dioxide fire extinguisher is its（）.

A.greater range
B.effectiveness on all types of fires
C.cleanliness
D.All of the above