List three sources of air pollution people cause.

Mobile Sources, Stationary Sources, and Area sources

In my own words.

Explanation:

Mobile sources such as cars and vehicles that run on oil release carbon monoxide which pollutes the air.

Stationary sources such as factories burn fossil fuels and release green-house gasses.

Area sources such as lumber and fire-wood places burn wood and release harmful gasses in the air.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.