单项选择题
When fighting a fire with a portable dry chemical fire extinguisher，the stream should be directed（）.
A.over the top of the flames
B.off a bulkhead into the fire
C.in front of the fire
D.at the base of the fire
单项选择题 When fighting a fire on a bulkhead using a portable carbon dioxide extinguisher，the stream should be directed at the（）.
单项选择题 When fighting a fire in an enclosed space，the hose team should crouch as low as possible to（）.
单项选择题 When electrical equipment is involved in a fire，the stream of dry chemicals should be（）.