Which one of the following is the most carcinogenic substance present in tobacco smoke?

The use of nicotine causes:

$S$ - Statement: Adolescence is the period between $12$ and $18$ years of age.
$R$ - Reason: Curiosity for excitement and adventure is necessary during adolescence.

Mention the function and source of Heroin.

Identify the components that induce nerve stimulation and muscle relaxation.

Smack is a drug obtained from the