Faye Phillips, age 10, of Pawnee, Okla.., for her question;

What happens to the air we breathe out?

The air we breathe out contains was the carbon dioxide, which is no use to us at all. Everybody breathes out this waste gas day and night  everybody all over the world. What's more, the animals too breathe out carbon dioxide and even plants pour waste carbon dioxide into the air. It is natural to wonder why all the air has not turned into carbon dioxide long ago.

It is the plant world which keeps this from happening, All green plants take in carbon dioxide during the daylight hours. They use it to make plant food. In the process, they return fresh oxygen to the air. True, they take in oxygen and give forth carbon dioxide as we do. But they give back far more oxygen than they need. This give and take between the plant and the animal kingdoms is what keeps us supplied with oxygen.