To understand what this number mean

To understand what this number means, we need to point out that one eucalyptus tree can decompose as much carbon dioxide as one human being exhales each day, and the resulting oxygen is returned to the air. So it would take three large eucalyptus trees to offset the carbon dioxide emitted by one human breath. We can see how important the plants around us are. We should grow plants in the city and take good care of them. Only plants can give the air back the oxygen that people take away. What's more, the amount of oxygen is still increasing, how can we not take plants seriously!Barium peroxide was first made from oxygen in the air in 1885. Today, oxygen is the basis of many sectors of the chemical industry; Steel mills already fill blast furnaces with pure oxygen instead of air; The number of machines that turn air into a liquid and extract oxygen from it is growing.