tough crust
41Mathematics 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… …
42Oldest dated rocks — The oldest dated rocks on Earth, as an aggregate of minerals that have not been subsequently melted or disaggregated by erosion, are from the Archean Eon. Such rocks are exposed on the surface in very few places.[1] There is some controversy… …
43Beef — For other uses, see Beef (disambiguation). An uncooked rib roast …
44List of Shadow Raiders planets — Shadow Raiders is a 3D CG animated TV cartoon based on the War Planets toy line. It features several planets.Planet TekLittle is known about Planet Tek, except that it is one of many planets which were consumed by the Beast Planet, as seen in the …
45Glossary of botanical terms — Many of the terms used in Wikipedia glossaries (often most) are already defined and explained within Wikipedia itself. However, lists like the following indicate where new articles need to be written and are also useful for looking up and… …
46dinosaur — /duy neuh sawr /, n. 1. any chiefly terrestrial, herbivorous or carnivorous reptile of the extinct orders Saurischia and Ornithischia, from the Mesozoic Era, certain species of which are the largest known land animals. 2. something that is… …
47hand tool — any tool or implement designed for manual operation. * * * Introduction any of the implements used by craftsmen in manual operations, such as chopping, chiseling, sawing, filing, or forging. Complementary tools, often needed as auxiliaries to… …
48hard — /hahrd/, adj., harder, hardest, adv., harder, hardest, n. adj. 1. not soft; solid and firm to the touch; unyielding to pressure and impenetrable or almost impenetrable. 2. firmly formed; tight: a hard knot. 3. difficult to do or accomplish;… …
49Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
50skin — n Skin, hide, pelt, rind, bark, peel can all denote an outer removable coat which adheres to and protects the inner tissues of a body or organism. Skin, the most general term, applies especially to the outer covering of animals, whether it is as… …
