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smoking

(Encyclopedia)smoking, inhalation and exhalation of the fumes of burning tobacco in cigars and cigarettes and pipes; in the 21st cent., vaping, the similar use of e-cigarettes, also has become common. Some persons ...

tuberculosis

(Encyclopedia)tuberculosis (TB), contagious, wasting disease caused by any of several mycobacteria. The most common form of the disease is tuberculosis of the lungs (pulmonary consumption, or phthisis), but the int...

stem cells

(Encyclopedia)stem cells, unspecialized human or animal cells that can produce mature specialized body cells and at the same time replicate themselves. Embryonic stem cells are derived from a blastocyst (the blastu...

blood

(Encyclopedia)blood, fluid pumped by the heart that circulates throughout the body via the arteries, veins, and capillaries (see circulatory system; heart). An adult male of average size normally has about 6 quarts...

food poisoning

(Encyclopedia)food poisoning, acute illness following the eating of foods contaminated by bacteria, bacterial toxins, natural poisons, or harmful chemical substances. It was once customary to classify all such illn...

forestry

(Encyclopedia)forestry, the management of forest lands for wood, water, wildlife, forage, and recreation. Because the major economic importance of the forest lies in wood and wood products, forestry has been chiefl...

cotton

(Encyclopedia)cotton, most important of the vegetable fibers, and the plant from which the fiber is harvested. Today the leading cotton states are Texas, Georgia, Mississippi, Arkansas, North Carolina, and Louisi...

circulatory system

(Encyclopedia)CE5 Circulatory system circulatory system, group of organs that transport blood and the substances it carries to and from all parts of the body. The circulatory system can be considered as compose...

Amazon, river, Peru and Brazil

(Encyclopedia)Amazon, Port. Amazonas ämäzōˈnəs [key], world's second longest river, c.3,900 mi (6,280 km) long, formed by the junction in N Peru's Andes Mts. of two major headstreams, the Ucayali and the short...

Platyhelminthes

(Encyclopedia)CE5 A. Planaria, representative of the phylum Platyhelminthes B. Internal anatomy of Planaria Platyhelminthes plătˌēhĕlmĭnˈthēz [key], phylum containing about 20,000 species of soft-bodied,...