a. a drug that increases the action of the central nervous system
b. a thick, sticky, dark fluid produced when tobacco burns
c. thickened white, leathery-looking spots on the inside of the
mouth that can develop into oral cancer
d. the addictive drug found in tobacco leaves
e. a cancer-causing substance
1. Nicotine 2.stimulant 3. Carcinogen. 4. Tar. 5.leukoplakia