The air reaches the tiny air sacs (alveoli) in the inner part of the lungs with any dust particles that avoided the defenses in the nose and airways. The air sacs are very important because through them, the body receives oxygen and releases carbon dioxide.
1 A full size keg holds about 15.5 gallons (165 12-oz cups) and is sometimes referred to as a 1/2 keg. 2  The full-size kegs typically start at about $100 for American draft beers. 3  Specialty beers, lagers and ales can cost from $125-$250.
Other keg sizes are also available. The 1/4 keg, also known as the pony keg, contains 7.75 gallons and serves 82 12-ounce or 62 16-ounce beer. The 1/6 keg contains 5.16 gallons and serves 56 12-ounce or 42 16-ounce beers. Using this information, the size and number of kegs needed to serve a specific number of people can be estimated.