Fireworks weren't just invented all of a sudden; they were gradually produced, with the inventions of other substances,such as gunpowder. Although many nations claim theinvention of gunpowder, it was actually invented by theChinese in the 9th Century.
来源：考试大
　　A Chinese cook happened to mix together three ingredientscommonly found in the kitchen - potassium nitrate (salt substitute), sulfur (flammable solid), and charcoal. The cooknoticed that, when ignited, the three ingredients burned viciously with a considerable force. The cook apparently also discovered that if these same ingredients were enclosed and then ignited, the combination exploded rather than burned, producing a loud bang. The chemical gunpowder spread throughout the world. There are many uses of gunpowder, in Europe were mainly used for canons during war. While the Europeans were using gunpowder for war, the Chinese used it for firecrackers and fireworks.来源：考试大