Why do people smoke? One reason is that people become addicted(成瘾) to cigarettes. The addictive substance(物质）in cigarettes is nicotine(尼古丁). When people smoke, the nicotine goes right into the blood stream and makes people feel comfortable. A smoker's body gets used to the nicotine, and if he stops smoking, he feels nervous. Many smokers try to stop smoking but because of the addiction to nicotine they feel so uncomfortable that they often find it too difficultto do so.
Another reason is that people simply enjoy smoking. Having a cigarette for many people means taking a break. For some people smoking becomes part of certain social rituals (礼仪), f or example, sending the cigarette after dinner. Many people enjoy smoking because it gives them something to do with their hands. Reaching for a cigarette, lighting it and flicking (弹掉) the ashes are special comfort in a situation where they feel nervous.
Many people also like the taste of tar (焦油) in cigarettes. However, it is the tar that causes cancer. While governments and health experts have tried to get people to give up smoking completely, cigarette manufacturers (生产商) have tried to keep selling them by producing cigarettes with less tar. Many people in western countries have welcomed these cigarettes since they found it hard to stop smoking and wanted to reduce the danger to their health.
