单项选择题
A.be jettisoned B.be dropped C.be dived D.be abandoned
The air cylinder bottles in the survival craft should b...
单项选择题The air cylinder bottles in the survival craft should be refilled with（）.
A.oxygen B.nitrogen C.compressed air D.nitrogen and oxygen
The (auto)ignition temperature is that temperature atwh...
单项选择题The (auto)ignition temperature is that temperature atwhich（）.
A.no spark or flame is required to ignite gas or vapor B.a fuel begins to give off explosive vapors C.a fuel if ignited will continue to burn D.a 1% mixture of the fuel with air will explode
Sulfuric acid is a（）.A.clear syrupy liquid with no odor...
单项选择题Sulfuric acid is a（）.
A.clear syrupy liquid with no odor B.colorless-to-brown liquid with a choking odor when hot C.colorless liquid with a pleasant fruity odor D.whitish liquid with a faint，pleasant odor
