Because it is flexible. Think about it; the ribs protect both the lungs and the heart. If the ribs were solid bone all the way around then unless you constantly break your ribs you wouldn't be able to expand the cheat to breath. Additionally your lungs would constrict the heart to a degree that it would function properly.
Evidence that you have accomplished a goal is: measurable
3) goals should be: realistic
Blaming your sister is an example of: projection
Your stressing your self out, you will wont start to lose your muscle mass
