单项选择题
What does the term head mean when applied to a fire pump?（）
A.Length of the discharge pipe B.Height of the discharge pipe C.Difference between the discharge and suction pressures D.Sum of discharge and suction pressures
单项选择题 What does blowing tubes accomplish?（）
单项选择题 What are the most important reasons for using water fog to fight fires?（）
单项选择题 Weight is considered during the periodic required inspection and servicing of（）.
