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
单项选择题 A petroleum liquid has a flash point of 135°Fahrenheit. This liquid is classed as a grade （）.
单项选择题 A flame screen（）.
单项选择题 （）shall be provided in every cargo tank and slop tank in accordance with the appropriate Resolutions.
