Air is fundamental for everyday activities and healthy living. We need air indoors and outdoors to breathe and survive. Air is a mixture of invisible, odorless, tasteless gases that surround the Earth. It has no shape of its own, but takes the shape of the object it fills. Even though air is invisible, it still has weight.
Air can be a light breeze, a strong wind, fill up an empty space, and carry sound.
All major buildings, schools, and homes need ventilation, which is the process of supplying outdoor air to the occupied areas indoors. However, one major concern is the pollution levels of indoor air. The levels of indoor air pollutants are at least 2-5 times greater, an occasionally higher than outdoor pollutant levels. It may take few minutes to download.