A.Effective even if ventilation is not shut downB.Will ……

单项选择题What is meant by the term overhaul in firefighting?（）

A.Slow down the spread of fire by cooling adjacent structures
B.Cover the fire with foam
C.Smother the fire with a blanket or similar object
D.Break up solid objects to ensure that any deep seated fires are extinguished

单项选择题What is best suited for fighting a fire in a ballast control room?（）

A.Automatic sprinkler system
B.Steam smothering system
C.Dry chemical system
D.Carbon dioxide system

单项选择题What is an advantage of using foam in fire fighting?（）

A.It is effective in controlling fire in flowing oil such as coming from a broken fuel line
B.It absorbs heat from materials that could cause reignition
C.Most foams can be used jointly with dry chemical extinguishing agents to attack a fire by two methods of extinguishment
D.Once the surface is blanketed with foam and the fire is extinguished，no further foam is required

单项选择题What is an advantage of using foam in fire fighting?（）

A.It is MOST effective on very hot oil fires where the temperatures of the liquid exceed 100°C (212°F)
B.Most foams can be used with dry chemicals to attack a fire by two methods
C.Foam is effective on combustible metal fires
D.Foam can be made with seawater or fresh water

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