Teen is a range that contains the most changes. Teenagers will have to change are two: first the changes in nature and caused by the surrounding factors, or the environment.
Adolescence is a period that has changed the most. Teens will have to change two things together is the first natural change. And turning caused by factors surrounding or environment.
Teenagers will be with the most changes. Teenagers are changed 2 together is the first is changed according to nature. Changes resulting from causes around or the environment.