单项选择题
The BEST method of applying foam to a fire is to（）.
A.spray directly on the base of the fire B.flow the foam down a nearby vertical surface C.sweep the fire with the foam D.spray directly on the surface of the fire
单项选择题 The atmosphere in a tank is too lean if it is（）.
单项选择题 The all-purpose nozzle will produce a fog spray when you（）.
单项选择题 Small quantities of flammable liquids needed at a work site should be（）.
