Задание

Choose the correct words.

There are over 4.000 in the tobacco smoke. Most of them are extremely to humans. The harmful chemicals have been found in the cigarettes including carbon monoxide, nitrates, ammonia, hydrogen cyanide, sulphur compounds, nitrosamines, hydrocarbons, vinyl chloride, etc. These chemicals together and form a sticky tar. The smell and colour of the cigarette are by the tar. In addition, this tar to skin, lungs and .