The answer is D because of smoking and the smoke fills places and the smoke is dangerous to breathe in. If you are younger than 18 and are using drungs it is against the law to do that. Finnally they increase spread of disease because you could have too much drugs.
hope this helped :)
alisa202
Answer:
Explanation:
Training thresholds refer to the level of intensity needed in order to stress the body enough to cause an adaptation or improvement in performance. ... The higher the training intensity within this zone the greater the adaptations.
They are there because people believe they are from not enough sleep but some people get them from genes. Genes are things you get from your parents.
Hope this helps!!
Serving size / servings per container