The cigarette releases 38 kinds toxic chemical substance when burning , among them harmful component has tar , carbon monoxide , nicotine , dioxin and pungency smoke fog etc. mainly.

• 把以下文段翻译成英语：香烟燃烧时释放38种有毒化学物质，其中有害成份主要有焦油、一氧化碳、尼古丁、二恶英和刺激性烟雾等。