It takes five hours to drive from Fort Worth to Midland which is a distance of 300 miles. What would be the average speed for this trip? Record your answer on the
grid.

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.