单项选择题
A.nitrogen B.oxygen C.carbon dioxide D.water vapor
Each inert gas system must be designed to supply the ca...
单项选择题Each inert gas system must be designed to supply the cargo tanks with a gas，or mixture of gasses，that has an oxygen content by volume of（）.
A.5% or less B.10% or less C.15% or less D.20% or less
Compared to the amount of concentrated foam liquid used...
单项选择题Compared to the amount of concentrated foam liquid used，the amount of low expansion mechanical foam produced is（）.
A.97 times greater B.94 times greater C.10 times greater D.2 times greater
Combustible gas indicators operate by drawing an air sa...
单项选择题Combustible gas indicators operate by drawing an air sample into the instrument（）.
A.over an electrically heated platinum filament B.where it is mixed with nitrogen C.where it is ignited by a sparking device D.where its specific gravity is measured
