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Arctic, the

(Encyclopedia)CE5 Arctic, the northernmost area of the earth, centered on the North Pole. The arctic regions are not coextensive with the area enclosed by the Arctic Circle (lat. 66°30′N) but are usually defi...

taiga

(Encyclopedia)taiga tīˈgə [key], northern coniferous-forest belt of Eurasia, bordered on the north by the treeless tundra and on the south by the steppe. This vast belt, comprising about one third of the forest ...

Sahel

(Encyclopedia)Sahel sähĕlˈ [key], name applied to the semiarid region of Africa between the Sahara to the north and the savannas to the south, extending from Senegal and Mauritania on the west, through Mali, N B...

mass extinction

(Encyclopedia)mass extinction, the extinction of a large percentage of the earth's species, opening ecological niches for other species to fill. There have been at least ten such events. The five greatest were thos...

Mittal, Lakshmi Narayan

(Encyclopedia)Mittal, Lakshmi Narayan, 1950–, Indian steel tycoon. He worked at his father's small Kolkata (Calcutta) steel mill before he bought (1976) a mill in Indonesia and began to build his steel empire. He...

Bentham, George

(Encyclopedia)Bentham, George bĕnˈthəm [key], 1800–1884, one of the greatest of English systematic botanists; nephew of Jeremy Bentham. He wrote Handbook of British Flora (1858) and, with W. J. Hooker, Genera ...

Bill and Melinda Gates Foundation

(Encyclopedia)Bill and Melinda Gates Foundation, philanthropic institution founded in 1994 by Microsoft chairman Bill Gates and his wife, Melinda, to improve the lives of the poor throughout the world, primarily th...

communications satellite

(Encyclopedia)communications satellite artificial satellite that functions as part of a global radio-communications network. Echo 1, the first communications satellite, launched in 1960, was an instrumented inflat...

Sunita, Narain

(Encyclopedia)Sunita, Narain, 1961–, Indian writer and environmentalist, b. New Delhi, India, graduated from University of Delhi, honorary degrees from Cranfield ...

neem tree

(Encyclopedia)neem tree or margosa tree, a fast-growing broad-leaved evergreen, Azadirachta indica, native to India and Myanmar. Its extracts have been used for centuries in Asia as pesticides, toothpaste, medicine...