单项选择题
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
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
