Because a cigarette contains tar, according to the national standard (GB) about 15~25mg (refers to the tar content of "medium" cigarettes). Among the harmful substances of cigarettes, "Nicotine" is well known. Many people do not know tar, but they know nicotine (also known as nicotine). How should we smokers smoke? The nicotine content in cigarettes is very low, only a few tens of milligrams. Strictly speaking, nicotine is one of the drugs. If the nicotine content in cigarettes is not about 10 mg, but dozens of MG, cigarettes have long been included in the category of "drugs. A certain amount of nicotine intake can kill people. However, coincidentally, at this time, the trace amount of nicotine can make people's central spirit produce excitement, heartbeat acceleration, concentration and active thinking. Some problems that cannot be considered at ordinary times can light a cigarette, it often inspires inspiration, which is the truth.