How to write a composition about respiratory system?

Everyone has a healthy body! Like a pot of water in the desert! If you cherish it, it will have infinite value, if you don't cherish it, it will be useless!

Many people are smoking now! Although the cigarette case says smoking is harmful to health! But there are still many people smoking! Cigarettes contain a lot of tobacco ingredients. When they are combined with oxygen through combustion, they will produce carbon monoxide (CO), carbon dioxide (CO2) and a lot of harmful substances, such as smoke and tar. Carbon monoxide is a poisonous gas. If people stay indoors with a lot of carbon monoxide, they will be dizzy, dizzy, weak in limbs, and even have difficulty breathing and die. Carbon dioxide is nontoxic, but inhaling a large amount of carbon dioxide will destroy the process of gas exchange between oxygen in alveoli and red blood cells in capillaries. It also has certain harm! Tar is a famous smoke poison! After the human body inhales tar, it will be adsorbed on the inner wall of respiratory tract and alveoli, which will not only release toxic substances, but also accumulate for many years. It will also block the respiratory tract and make it difficult to breathe! The harm of smoking is not only these, but also many. Therefore, I appeal here: "cherish life and be healthy and upward"!

Air pollution, a health killer, is also sharp. With the rapid development of science and technology today, air pollution is directly proportional to the development of science and technology! At present, the exhaust emissions of some factories far exceed the national standards, leading to the occurrence of natural disasters such as acid rain, and the incidence of respiratory diseases is increasing year by year. ...

If each of us cares about our health and protects the natural environment, then we will live under the same beautiful blue sky! I sincerely hope that people can cherish the health we have. What a wonderful thing this will be!

Life is beautiful, and health can't be ignored. Let's keep exercising for an hour every day, so as to live a healthy life together tomorrow!

Friend, do it!