The oxygen we breath is a free gift from the plant world. Green plants use carbon dioxide, the waste gas we breath out, to make the sugar which is their basic food. In the process, they return oxygen to the air. A lush forest pours tons of oxygen into the air through every summer day and this vital gas is wafted by the breezes around the world.

This wonderful give and take between the plant and animal world makes life possible on our planet, The animal world gives its waste carbon dioxide to the plant world and the plant world gives its waste oxygen to the animal world.