When you breathe in, or inhale, your diaphragm contracts and moves downward. This increases the space in your chest cavity, and your lungs expand into it. The muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.
I think I did everything pretty well. I only wish I could do one thing better because I didn't like how it came out. I mostly made errors in commas and sometimes made errors in spelling. But after all that I think I did good.
