单项选择题
A.The fire pump
B.Exposed hard piping
C.The hydrant valve
D.The fire hose
单项选择题 What is the MOST important consideration when determining how to fight an electrical fire?（）
单项选择题 What is the most important characteristic of the extinguishing agent in fighting a class C fire?（）
单项选择题 What is required in addition to the heat，fuel，and oxygen of the fire triangle to have a fire?（）