A、It is a powerful and fast-acting drug. B、It causes the familiar yellow and brown stain. C、Increased heart rate, and blood dise

Smoking is the most important cause of disease and death in the UK. The Health Education Authority states that, in England alone, there are 110,000 deaths caused by smoking every year. The main causes of death are lung cancer, and heart disease.
    The main harmful ingredients in cigarettes are as follows: First of all, tar, which is used in road- making: once inhaled, smoke condenses into liquid. And about 70 percent of the tar in a cigarette is deposited in a smoker’s lungs. Tar is a sticky brown substance which can stain smokers’ fingers and teeth that familiar yellow-brown color.
    Next, nicotine: nicotine is a powerful and fast-acting drug, and is the substance in tobacco which causes addiction among smokers. When tobacco smoke is inhaled, nicotine is absorbed into the bloodstream. The immediate effects include increased heart rate, and increased blood pressure.