All are found in the material produced when a cigarette burns, they are all harmful, but only C is addictive. Nicotine affects the brain by acting as a stimulant and people who smoke regularly find it difficult to live without this regular stimulation, in this way they become addicted. Nicotine is a very poisonous substance, shown by the fact that it is possible to make a very powerful insecticide out of a few cigarette ends boiled up in water!
