单项选择题
A.trichloromethane B.sulfuric chlorohydrin C.chlorine gas D.4-methyl phenol
A safe fuel system must（）.A.prevent engine overheatingB...
单项选择题A safe fuel system must（）.
A.prevent engine overheating B.have proper air/gasoline fuel mixture ratio C.be liquid- and vapor-tight D.supply sufficient air to the intake manifold
A petroleum liquid has a flash point of 135°Fahrenheit....
单项选择题A petroleum liquid has a flash point of 135°Fahrenheit. This liquid is classed as a grade （）.
A.B flammable liquid B.C flammable liquid C.D combustible liquid D.E combustible liquid
A flame screen（）.A.permits the passage of vapor but not...
单项选择题A flame screen（）.
A.permits the passage of vapor but not of flame B.prevents the passage of flammable vapors C.prevents inert gas from leaving a tank D.permits vapors to exit but not enter a tank
