单项选择题
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
Butadiene，inhibited，is labeled as a（）.A.combustible liq...
单项选择题Butadiene，inhibited，is labeled as a（）.
A.combustible liquid B.flammable gas C.flammable liquid D.flammable solid
Before starting a gasoline engine on a motorboat，you sh...
单项选择题Before starting a gasoline engine on a motorboat，you should make sure for safety that（）.
A.the gasoline tank is full B.the bilges，cabins，etc. are thoroughly ventilated C.you have fresh water on board D.Each of the above is followed
Before entering a tank，always check the vapor content（）...
单项选择题Before entering a tank，always check the vapor content（）a combustible gas indicator.
A.with B.by C.of D.for
