单项选择题
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
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
