Foam extinguishes a fire mainly by（）.

A.smothering the burning material
B.chemical combination with burning material
C.absorbing the burning material
D.organic destruction of the burning material

A.shutting off the air supply
B.cooling the fuel to below ignition temperature
C.dispersing the fuel
D.removing the source of ignition

A.utilizing carbon dioxide or dry chemical fire extinguishers
B.utilizing soda and acid fire extinguishers
C.blowing the flames out
D.letting it burn itself out