Smoking is harmful, not only to human health but also to society. As long as there are signs of life, any organized organism must breathe, exhale carbon dioxide in the body, inhale oxygen in the air, and carry out metabolism to maintain normal life activities. Non-smokers can breathe a lot of fresh air every day; However, people who smoke regularly do not enjoy the benefits of nature. What they breathe in is not fresh air, but toxic gas polluted by smoke.

Tobacco leaves contain toxic nicotine, also called nicotine. 1 g nicotine can poison 300 rabbits or 500 mice. If people are injected with 50 milligrams of nicotine, they will die.

Smoking is the most harmful to the respiratory tract, and it is easy to cause laryngitis, bronchitis, emphysema and other diseases. When smoking, smoke enters from the mouth, passes through the throat, trachea and bronchus, and enters the blood.

Smoking can make men lose Y chromosome and increase the risk of cancer. Medical research shows that smoking can make young college students lose their memories and feel depressed. With the decline of these physical functions, the competitiveness of college students will decline day by day, which will not meet the development and needs of modern society and even be eliminated by society. So college students should not smoke.