We might not have seen air, but, surely we must have felt its presence in so many ways. We notice it when the leaves of the trees rustle or the clothes hanging on a clothes-line sway. Pages of an open book begin fluttering when the fan is switched on. The moving air makes it possible for us to fly our kite. Winnowing is more effective in moving air. We may have noticed that during storms the wind blows at a very high speed. It may even uproot trees and blow off the rooftops.

 All living things require air. It is one of the most important component of our life.