Gap - filling
People have smoked for a long time now. The tobacco which is used to make cigarettes was the first grown in what is now part of the United States. Christopher Columbus, who (1)..... American, (2)..... Indians smoking, soon the dried leaves were transported to Europe where smoking began to catch on. (3)..... the late 1800s, the Turkish made cigarettes popular.
Cigarette smoke contains at least (4)..... harmful subtances, tar and nicotine. Tar, which forms (5)..... the tobacco burns, damages the lungs (6)...... therefore affects breathing. Nicotine, which is found in the leaves, causes the (7)..... to beat faster and increases the breathing rate.
Smoking cigarettes is dangerous. The US Publich Health Service stated that (8)..... smoking is the cause of lung cancer and several (9)..... deadly diseases. Many government in the world now require that each package of cigarettes bears s special warning about the (10)..... of smoking.