单项选择题
The primary method by which water spray puts out fires is by（）.
A.removing the oxygen B.cooling the fire below the ignition temperature C.removing combustible material D.diluting combustible vapors
单项选择题 The primary function(s) of an automatic sprinkler system is(are) to（）.
单项选择题 The preferred type of pollution control for oil spills on the water is(are) （）.
单项选择题 The preferred agent used in fighting a helicopter crash fire is（）.
