春节,又是燃放鞭炮的热闹时节。燃放鞭炮是件开心的事,但若不注意安全,就有可能伤人、引起火灾等。所以,燃放鞭炮千万要小心。危险等级▲▲▲鞭炮内装的是黑色火药,主要成分为硝酸钾、硫磺和木炭。这三种粉末混合物易燃、易爆,一经明火接触,即能引起燃烧和爆炸。 Chinese New Year, but also lively fireworks season. Setting off firecrackers is a happy thing, but if you do not pay attention to safety, you may injure others and cause a fire. Therefore, fireworks must be careful. Hazard Class ▲▲▲ The firecrackers contain black gunpowder. The main ingredients are potassium nitrate, sulfur and charcoal. The three powder mixtures are flammable and explosive, which can cause burning and explosion upon contact with open flame.