Why do teenagers use drugs

Teenagers can addicted to drugs by peer pressure from their friends to try it. Sometimes they use drugs to try to escape the pressures of life like Family, School, etc. But in turn, they end up messing up their bodies and filling them with dangerous and foreign substances.

because they fear that if they don't take part in that they'll feel left out or uncool many of them are aware of the effects drugs can give them but they refuse to stop because they think that their  social reputation might be ruined

Explanation:

b) the heart is a pump made of muscle and that is difficult to grow in the lab.