单项选择题
A.class "A" fires B.class "B" fires C.class "C" fires D.class "D" fires
Which of the following gases represents the greatest th...
单项选择题Which of the following gases represents the greatest threat to personnel safety in an engine room where the exhaust is leaking from a diesel engine?（）
A.Carbon dioxide B.Carbon monoxide C.Carbon trioxide D.Hydrogen sulfide
Seawater may be used for drinking water （）.A.at a maxim...
单项选择题Seawater may be used for drinking water （）.
A.at a maximum rate of two ounces per day B.after mixing with an equal quantity of fresh water C.if gather during or immediately after a hard rain D.under no circumstance
A class "D" fire would be considered as burning （）.A.wo...
单项选择题A class "D" fire would be considered as burning （）.
A.wood B.oil C.electrical equipment D.magnesium
