We can’t live without
air. No air means death at once. Bad air means bad health. We must have fresh
air to keep well and strong. A crowded, stuffy room soon gives one a headache. Why
is this? .It is because we are
breathing bad air. The air we breathing out is full of a poisonous gas. In the open
air this gas is blown away by the wind. But in a shut room it can’t get away. We
breathe it in again and again. This makes us feel sleepy. It gives us a headache.
When we get out again into the fresh air, we feel all right. But people living long
in bad air get really ill. Their lungs get diseased, and they may die. We need fresh
air to purify our blood and give it more life. So we should be out-of -doors as
much as we can. In a room, keep the windows open.