Though 80% of the earth's surface is covered with water, only 1% of it is fresh water. It's only 1% that we can use for drinking, irrigating, washing etc. So, it's very important that we conserve...
We all have to make a conscious effort to protect the environment. Otherwise from where will we get the water to drink and the fresh air to breathe? In fact water levels have already started to drop...
The cells in your body need oxygen to live. The oxygen you breathe into your lungs gets put into your blood. Your heart then pumps the blood carrying the oxygen to all the cells in your body.