Why do antibiotics become less effective overtime?

yes

Explanation:

Your body can start rejecting them over time and if taken too much can kill any "good" bacteria left in your body.

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.