Question

Respiration is a process of producing energy by the oxidation of food human respiratory system provide oxygen to the blood for for the supply to the all cells of the body now answer the questions on the basis of the basis of the above extract 1. why some people experience difficulty in breathing and 2.
what steps should be taken to avoid such problem

Answer 1

not only the food provides oxygen.....if he had breathed in a very polluted area he may experience the difficulty in breathing