单项选择题
A.cutting off the supply of oxygen
B.removing the fuel
C.cooling below the ignition temperature
D.spraying with water
单项选择题 Multiple fire pumps may be used for other purposes provided that one pump is（）.
单项选择题 Large volumes of carbon dioxide are safe and effective for fighting fires in enclosed spaces，such as in a pumproom，provided that the（）.
单项选择题 Inflatable liferafts are less maneuverable than lifeboats due to their（）.