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

List the harmful effects caused by alcohol and drug abuse.

These are known for their effects on the cardiovascular system.

Which of the following side effects is $NOT$ observed in males due to the excessive use of anabolic steroids?

The initial stage of drug addiction is

Nicotine is an alkaloid that enters the body through smoking. How many of the following characteristics are associated with its effects?
$(i)$ Increases blood pressure
(ii) Decreases respiratory rate
(iii) Causes cancer of the lungs,throat,and bladder
(iv) Induces allergies
$(v)$ Can cause emphysema
(vi) Decreases the level of $O_2$ in the blood