One company states that it makes the best staplers. To prove it, they use the stapler to staple a thousand papers and compare it to a competitor. The competitor’s stapler jammed 3x whereas their stapler only jammed once. A: Independent Variable:
B: Dependent Variable:

A: Independent Variable

Explanation:

A: Independent Variable

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.