We need oxygen to live. It is found in the air around us. Oxygen is needed to break down the digested food.

Respected system 

Like depends on oxygen gas present in the air. Oxygen plays an important role of releasing or breathing system. The nose, windpipe and lungs are the main organs of the respiratory system.

As we inhale fresh air through nose it goes down the throat and wind pile and reaches the lungs. In the lungs oxygen present in the system is passed into the blood which takes it to various parts is passed into the blood which takes it to various parts of the body. This oxygen combines with food that we eat and releases energy. Carbon dioxide is formed as a waste product which is brought back to the lungs by blood. From there it is exhaled breathed put through nose.

Helping a fire to burn while blowing                     Have you ever seen a village woman lighting her the fire. Why? Complete burning of the fuel in the chullah takes place when more air is supplied. More heat is given out and cooking becomes faster. Cooling by blowing when we have to drink hot coffee or soup what do we normally do we blow out air from our mouth. What happens? The coffee or or soup becomes cool after some time. Why. The water vapour in our the  air we breathe out makes the heat coming out of the air we breathe out makes the heat coming out of the hot coffee or soup escape faster. So blowing air from the mouth coals the hot drinks