（一）水水是来源丰富的灭火剂。水在灭火过程中受热蒸发成水蒸汽时 ,需要吸收大量的热能 ,因此水具有显著的冷却作用 ,能促使燃烧物质的温度降低到燃烧点以下。水在灭火中不仅起到降温作用 ,而且还能产生大量水蒸汽。水蒸汽是一种不燃气体 ,它在燃烧区内可以稀释可燃气体的浓 (A) water is a source of rich fire extinguishing agent. When water evaporates into water vapor during the fire extinguishing process, it needs to absorb a large amount of heat energy. Therefore, the water has a significant cooling effect and can cause the temperature of the burning material to be reduced below the burning point. Water in the fire extinguishing not only play a cooling effect, but also produce large amounts of water vapor. Water vapor is a non-flammable gas that dilutes the concentration of combustible gas in the combustion zone