单项选择题
A.greater range B.effectiveness on all types of fires C.cleanliness D.All of the above
An ABC dry chemical fire extinguisher would be LEAST ef...
单项选择题An ABC dry chemical fire extinguisher would be LEAST effective against a fire in（）.
A.a mattress B.spilled liquids such as oil or paint C.high voltage electrical gear D.a trash can
All portable fire extinguishers must be capable of bein...
单项选择题All portable fire extinguishers must be capable of being（）.
A.carried by hand to a fire B.carried or rolled to a fire C.recharged in the field D.used on class 'B' fires
All of the following are part of the fire triangle EXCE...
单项选择题All of the following are part of the fire triangle EXCEPT（）.
A.electricity B.fuel C.oxygen D.heat
