Answer:
False
Explanation:
Body Composition is the difference of fat to lean muscle in the human body
Principle of Reversibility is the decline of skill and fitness level due to taking a break from exercise or being inactive.
It is called such because all the result of hardwork and labor done to achieve and maintain one's skill and fitness level will be reversed because said fitness regime is not maintained; making the body lax, eventually declining in skill performance and fitness level.
The veins is the part that holds the blood, mostly.