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9/11

(Encyclopedia)9/11, the terrorist attacks on Sept. 11, 2001, in the United States, and the associated events and impact of those attacks. The attacks, which were carried out by agents of Al Qaeda (a militant Islami...

infrared astronomy

(Encyclopedia)infrared astronomy, study of celestial objects by means of the infrared radiation they emit, in the wavelength range from about 1 micrometer to about 1 millimeter. All objects, from trees and building...

Connecticut, state, United States

(Encyclopedia)CE5 Connecticut kənĕtˈĭkət [key], southernmost of the New England states of the NE United States. It is bordered by Massachusetts (N), Rhode Island (E), Long Island Sound (S), and New York (W)...

whale

(Encyclopedia)whale, aquatic mammal of the order Cetacea, found in all oceans of the world. Members of this order vary greatly in size and include the largest animals that have ever lived. Cetaceans never leave the...

gem, ornamental mineral or organic substance

(Encyclopedia)gem, commonly, a mineral or organic substance, cut and polished and used as an ornament. Gems also are used as seals (items of assurance) and as talismans (good-luck charms). For birthstones, see mont...

hydrogen

(Encyclopedia)hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...

satellite, artificial

(Encyclopedia)CE5 A. Nimbus weather satellite B. Syncom communications satellite satellite, artificial, object constructed by humans and placed in orbit around the earth or other celestial body (see also space ...

air pollution

(Encyclopedia)air pollution, contamination of the air by noxious gases and minute particles of solid and liquid matter (particulates) in concentrations that endanger health. The major sources of air pollution are t...

Turkey , country, Asia and Europe

(Encyclopedia)CE5 Turkey, Turk. Türkiye türˌkēyĕˈ [key], officially Republic of Turkey, republic (2015 est. pop. 78,271,000), 301,380 sq mi (780,574 sq km), SW Asia and SE Europe. It borders on Iraq (SE), ...

automobile

(Encyclopedia)CE5 Automobile chassis CE5 Two views of a six-cylinder automobile engine automobile, self-propelled vehicle used for travel on land. The term is commonly applied to a four-wheeled vehicle desig...