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Every year，forest fires happen at times in different places.Local firefighters have to
（1） quickly and put out the fires.The fires are so （2） that lots of trees and houses may be burned.They even cause the deaths of firefighters.Most of the firefighters are so young.Their deaths touch our hearts all over China.
Forest fires are common in spring.People believe there are many （3） for forest fires.Warm and dry weather，thick grass and trees and hot winds can easily make fires happen.As far as we know，90% of forest fires are caused （4） humans.During the holidays of Qingming，millions of people （5） to their hometowns to honor ancestors.The risks of fires in mountains are higher.So experts remind people to be more careful.
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