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71Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
72zinc processing — Introduction preparation of the ore for use in various products. Zinc (Zn) is a metallic element of hexagonal close packed (hcp) crystal structure and a density of 7.13 grams per cubic centimetre. It has only moderate hardness and can …
73environment — environmental, adj. environmentally, adv. /en vuy reuhn meuhnt, vuy euhrn /, n. 1. the aggregate of surrounding things, conditions, or influences; surroundings; milieu. 2. Ecol. the air, water, minerals, organisms, and all other external factors… …
74volcano — /vol kay noh/, n., pl. volcanoes, volcanos. 1. a vent in the earth s crust through which lava, steam, ashes, etc., are expelled, either continuously or at irregular intervals. 2. a mountain or hill, usually having a cuplike crater at the summit,… …
75biblical literature — Introduction four bodies of written works: the Old Testament writings according to the Hebrew canon; intertestamental works, including the Old Testament Apocrypha; the New Testament writings; and the New Testament Apocrypha. The Old… …
76Asbestos — For other uses, see Asbestos (disambiguation). Fibrous asbestos on muscovite …
77Formation and evolution of the Solar System — Artist s conception of a protoplanetary disk The formation and evolution of the Solar System is estimated to have begun 4.568 billion years ago with the gravitational collapse of a small part of a giant molecular cloud …
78Abiogenesis — Primordial soup redirects here. For the board game, see Primordial Soup (board game). Origin of life redirects here. For views on the origins of life outside the natural sciences, see Creation myth. Pre Cambrian stromatolites in the Siyeh… …
799/11 Truth movement — Supporters of the 9/11 Truth movement at a Los Angeles demonstration, October 2007 9/11 Truth movement is a collective name for loosely affiliated organizations and individuals who question the accepted account of the September 11, 2001,… …
80Marine pollution — While marine pollution can be obvious, as with the marine debris shown above, it is often the pollutants that cannot be seen that cause most harm. Marine pollution occurs when harmful, or potentially harmful effects, can result from the entry… …
