Air is all around us. It is around us when we walk and play. From the moment we are born, air surrounds us. When we sit down, it is around us. When we go to bed, air is also around us. No matter where we are on earth, air surrounds us. We live in air.All living things need air. Living things cannot live without air. We can go without food or water for a few days, but we cannot live for more than a few minutes without air. When we are working or running, we need more air. So we breathe faster than usual. When we are asleep, we need less air. People can live without food or water for______.