【问】 At last firemen have put out a big forest fire in California. (New Concept English，Book2，L.53)

fire为不可数名词，如There is no smoke without fire.为什么上面句子里的fire与不定冠词连用?

【答】 当fire作“火”、“火焰”解时是个不可数名词。但是，当fire作“具体的火灾”和“炉火”解时，它是个可数名词，例如forest fires(森林火灾)。

1. There was a fire in the next street last night. (Palmer)

昨天夜里邻街着火了。

2. A single spark can start a prairie fire. (Mis)

星星之火可以燎原。