单项选择题
Fires involving combustible metals are classified as （）.
A.class "A" fires B.class "B" fires C.class "C" fires D.class "D" fires
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?（）
单项选择题 Seawater may be used for drinking water （）.
单项选择题 A class "D" fire would be considered as burning （）.
