Answer to Question 1
Water is the most important nutrient because it is involved in almost every vital body process: in digesting and absorbing food, in producing energy, in the circulatory process, in regulating body heat and electrolyte balance, in removing waste products, in building and rebuilding cells, in transporting essential nutrients, and in cushioning joints and organs. Water is contained in almost all foods, but primarily in liquid foods, fruits, and vegetables. Caffeine-containing drinks are also acceptable as a water source
Answer to Question 2
As it burns, tobacco produces tar, a thick, sticky dark fluid made up of several hundred different chemicalsmany of them poisonous, some of them carcinogenic (enhancing the growth of cancerous cells). As you inhale tobacco smoke, tar and other particles settle in the forks of the branch-like bronchial tubes in your lungs, where precancerous changes are apt to occur. In addition, tar and smoke damage the mucus and the cilia in the bronchial tubes, which normally remove irritating foreign materials from your lungs.
Smoke from cigarettes, cigars, and pipes also contains carbon monoxide, the deadly gas that comes out of the exhaust pipes of cars, in levels 400 times those considered safe in industry. Carbon monoxide interferes with the ability of the hemoglobin in the blood to carry oxygen, impairs normal functioning of the nervous system, and is at least partly responsible for the increased risk of heart attacks and strokes in smokers.