Smoke has something for people in poor health, nicotine.

　　Nicotine in a cigarette can kill a mouse, 25 g of nicotine in cigarettes can kill a few cows, 40 to 60 mg of pure nicotine can kill a person.

　　The dangers of nicotine is also quite big, it can cause stomach or other stomach disease; Also can make the person causes heart disease cause rhythm of the heart is not straight; The outbreak of serious still can cause cancer.

　　Cigarettes are hidden in the invisible killer, around us are all should be vigilant.

　　According to scientists, the chemical composition of tobacco contains hundreds of complex, most harmful to human body, including tar, nicotine, phenols, alcohols, acids, aldehyde is 40 kinds of toxic and carcinogenic substance. Smoke after the fire, smoke, contains the chemical composition of tobacco in all, at the same time than the tobacco itself and added some harmful substances, such as carbon monoxide, tobacco tar and so on. This is because in addition to the tobacco itself, in the process of cigarette made, to add some cocoa in raw materials, liquorice, sugar, glycerin, such as ethylene glycol, moist, taste fragrance and combustion-supporting material. Although these additive itself is harmless, but changed in the process of combustion. For example, in the back of the rat with cocoa after burning smoke oil, can grow skin tumor. Glycyrrhizic acid in glycyrrhiza after burning, with other ingredients, can generate have carcinogenic polycyclic aromatic hydrocarbons. Sugar increased after combustion with tobacco tar, and the product of sugar after combustion is an important carcinogens in tobacco. Glycerin and glycol after the burning of the material, not only can make smokers bladder cancer, and the acrolein inhibits the trachea and cilia secretion from the lungs, thereby increase the chances of suffering from bronchitis and emphysema, and make people with both became seriously ill.

　　Smoke harm to people is how great! So we can't smoke. Stop smoking, the benefit of future generations.

　　烟里有一种对人身体不好的东西——尼古丁。

　　一枝香烟中的尼古丁可以毒死一只小白鼠，25g的香烟里的尼古丁可 毒死几头牛，40至60毫克纯尼古丁可以毒死一个人。

　　尼古丁的危害也是相当的大，它可以引起胃痛或其它胃病;还会使人引起心律不正诱发心脏病;严重的还可能引起癌症的爆发。

　　香烟是隐藏在我们身边的隐形杀手，是大家所应警惕的。

　　据科学家测定，烟草中含有数百种复杂的化学成分，大部分对人体有害，其中焦油、尼古丁、酚类、醇类、酸类、醛类等40种是有毒和有致癌作用的物质。烟在点燃后，所产生的烟雾，包含了烟草中所有的化学成分，同时比烟草本身又增加了一些有害物质，如一氧化碳和烟焦油等。这是因为除烟草本身外，在制成卷烟的过程中，要在原料中加入一些可可、甘草、糖、甘油、乙二醇等调味、湿润、产香、助燃物质。这些添加剂虽然本身无害，但在燃烧过程中却起了变化。例如，在鼠背涂上可可燃烧后产生的烟油，可长出皮肤瘤。甘草中的甘草酸在燃烧后，与其他成分化合，可生成有致癌作用的多环芳烃。糖与烟草一起燃烧后增加了焦油量，而糖燃烧后的产物是烟中的一个重要致癌物。甘油和乙二醇在燃烧后的物质，不但可能使吸烟者患膀胱癌，而且所产生的丙烯醛可抑制气管和纤毛分泌物从肺内排出，从而增加患气管炎和肺气肿的机会，并使患有这两种病的人病情加重。

　　烟对人的危害是多么大啊!所以我们不能吸烟。杜绝吸烟，造福后人。