Halon extinguishers used on a class C fire should be directed at the（）.

A.allowing better access in an emergency
B.eliminating potential fuel sources
C.eliminating trip hazards
D.improving personnel qualifications

A.sweep flames away with water spray
B.shut off the leak
C.use a chemical foam fire extinguisher
D.call the local fire department

A.should be worn while fighting a fire
B.can be used in atmospheres deficient in oxygen
C.filter contaminants from air that is to be breathed
D.may be substituted for a self-contained breathing apparatus