15. Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?

Yes, friends can influence one to take drugs and alcohol. A person can take the following steps for protecting himself/herself against drug abuse:

$⇒$ Increase your will power to stay away from alcohol and drugs. One should not experiment with alcohol for curiosity and fun.
$⇒$ Avoid the company of friends who take drugs.
$⇒$ Seek help from parents and peers.
$⇒$ Take proper knowledge and counseling about drug abuse. Devote your energy to other extra-curricular activities.
$⇒$ Seek immediate professional and medical help from psychologists and psychiatrists if symptoms of depression and frustration become apparent

16. Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.

Drug and alcohol consumption has an inherent addictive nature associated with euphoria and a temporary feeling of well-being. Repeated intake of drugs increases the tolerance level of the body’s receptors, leading to more consumption of drugs.