單項(xiàng)選擇題

Foam-type portable fire extinguishers are most useful in combating fires involving（）.

A.solid materials such as wood or bales of fiber
B.inflammable liquids
C.electrical equipment
D.metallic solids

你可能感興趣的試題

Foam is a very effective smothering agent and（）.

A.it provides cooling as a secondary effect
B.works well on extinguishing electrical fires
C.can be used to combat combustible metal fires
D.All of the above

單項(xiàng)選擇題

Foam extinguishes a fire mainly by（）.

A.cooling
B.chemical action
C.smothering
D.inerting the air