The role of air in life: air can help combustion (because there is oxygen in the air); Air is a necessary condition for the survival of animals and plants on the earth, and the breathing of animals and the function of plant light platform are inseparable from air; Air has pressure, and pressure plays an important role in human production and life. Air has buoyancy, so birds and planes can fly in the air; The atmosphere can block all kinds of rays from space and protect life on earth from them.