Exercise and moving in general typically puts force on bones the same way that a car puts force in its suspension. It compacts bones slightly and leads to new tissue (bone) growth, similar to how muscles grow.
I think the answer is A although I am not entirely positive
Answer:
heredity
Explanation:
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents.
I think its mandatory becuase at our age, we're going through hormonal changes and hella body changes. We're gaining weight, losing it and staying fit and healthy is mandatory to be able to maintain that. By gaining too much weight at a young age, you can cause many future health problems. don't get me wrong, every body is beautiful and everyone was born different but we just need that little bit of exercise to keep our blood pumping and keep up healthy.
They may experience irritability and depression because when a person constantly smokes, his/her brain begins to rely on the chemicals it gets from the person smoking, which results in the brain "getting lazy" and not producing the chemicals anymore. If the person were to suddenly quit, the brain would lack in the chemicals it had stopped producing, making the person feel constantly annoyed and depressed because of the chemical imbalance.