Calcium rich food will be most beneficial to prevent osteoporosis. For eg, milk, cheese, cereal, soybean, spinach etc.
Fewer job opportunities for the mother, unfortunately, especially if she is pregnant, because people judge, and they won't think she is responsible since she is underage and with child. With the father, it's not like they'll know right away, and they can just walk away and not be bothered with the subject again, while the mother will have to find a job and either manage to balance school, or drop out. The parents don't have to do anything, but they can support there children, but it's still not going to affect if they get job offerings or not.
Answer:
Because for whatever reason, some women feel that they need to become as skinny as a pencil to be noticed. That, mixed with the uncertainty and hormonal unbalances of puberty, and they'll literally run themselves into the ground trying to reach the unattainable standard for beauty that society (mainly men) have set.
A Rep (repetition) is one complete motion of an exercise.
For example, if the teacher asks you to do 10 by 4 push-ups, then a "rep" would be your first 10 push-ups finished.