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coral reefs

(Encyclopedia)coral reefs, limestone formations produced by living organisms, found in shallow, tropical marine waters. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an...

frog

(Encyclopedia)frog, common name for an amphibian of the order Anura. Frogs are found all over the world, except in Antarctica. They require moisture and usually live in quiet freshwater or in the woods. Some frogs ...

occupational disease

(Encyclopedia)occupational disease, illness incurred because of the conditions or environment of employment. Unlike with accidents, some time usually elapses between exposure to the cause and development of symptom...

Mediterranean Sea

(Encyclopedia)CE5 Mediterranean Sea [Lat.,=in the midst of lands], the world's largest inland sea, c.965,000 sq mi (2,499,350 sq km), surrounded by Europe, Asia, and Africa. Some of the most ancient civilizat...

public health

(Encyclopedia)public health, field of medicine and hygiene dealing with the prevention of disease and the promotion of health by government agencies. In the United States, public health authorities are engaged in m...

genetic engineering

(Encyclopedia)CE5 Genetic engineering: Gene-splicing techniques genetic engineering, the use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biologica...

water supply

(Encyclopedia)water supply, process or activity by which water is provided for some use, e.g., to a home, factory, or business. The term may also refer to the supply of water provided in this way. In the United Sta...

swine

(Encyclopedia)swine, name for any of the cloven-hoofed mammals of the family Suidae, native to the Old World. A swine has a rather long, mobile snout, a heavy, relatively short-legged body, a thick, bristly hide, a...

Rhine

(Encyclopedia)Rhine rīn [key], Du. Rijn, Fr. Rhin, Ger. Rhein, Lat. Rhenus, principal river of Europe, c.820 mi (1,320 km) long. It rises in the Swiss Alps and flows generally north, passing through or bordering o...

Great Lakes, North America

(Encyclopedia)Great Lakes, group of five freshwater lakes, central North America, creating a natural border between the United States and Canada and forming the largest body of freshwater in the world, with a combi...