problems with teenagers working

should teenageras work? the answer is NO.  there are many problems happened at them.
Jason Ferry,when he was a high school junior, he acknowledged he had no time to study when big tests was comeing. that really effect his course. inaddition,the National Research Council and the Institute of Medicine ----find that when teenagers work more than 20 hours a week, it leads to lower grades.
http://web.jjay.cuny.edu/awinson/teens-working.htm

if only it,  many people will say, what's wrong with teengaers working,  is a higer grades  more important than cou social experience ? not at all.

but when you see after example. you will know why.
there are 6 reasons in teenagers body.

• Activity in the teen brain is similar to the 0-3 fundamental development years
• The brain might not fully develop until 25 years old
• The brain develops by trial and error
• Hormone type and level influence choices and behavior
• Trauma affects brain development
• Adults should expect teens to act like teens

those courses  will make them in trouble. like smokeing, drink excessively.
form http://www.officer.com/web/online/On-the-Street/Whats-Wrong-with-Teenagers/21$55583