单项选择题
Gasoline vapor tends to collect（）.
A.above the floor plates of the bilges B.above the carburetor level C.at the lowest point of the bilge areas D.at no particular level
单项选择题 Gasoline tanks should be filled（）.
单项选择题 Gasoline fumes tend to（）.
单项选择题 Each ship having an inert gas system must have a portable instruments to measure concentrations of hydrocarbon vapor in inert atmospheres and also to measure（）.
