upper-limit position
11respiration, human — ▪ physiology Introduction the process by which oxygen is taken up and carbon dioxide discharged. The design of the respiratory system The human gas exchanging organ, the lung, is located in the thorax, where its delicate tissues are… …
12keyboard instrument — ▪ music Introduction any musical instrument on which different notes can be sounded by pressing a series of keys, push buttons, or parallel levers. In nearly all cases in Western music the keys correspond to consecutive notes in the… …
13pre-Columbian civilizations — Introduction the aboriginal American Indian (Mesoamerican Indian) cultures that evolved in Meso America (part of Mexico and Central America) and the Andean region (western South America) prior to Spanish exploration and conquest in the 16th …
14Doomsday argument — World population from 10,000 BC to AD 2000 The Doomsday argument (DA) is a probabilistic argument that claims to predict the number of future members of the human species given only an estimate of the total number of humans born so far. Simply… …
15star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
16South Asian arts — Literary, performing, and visual arts of India, Pakistan, Bangladesh, and Sri Lanka. Myths of the popular gods, Vishnu and Shiva, in the Puranas (ancient tales) and the Mahabharata and Ramayana epics, supply material for representational and… …
17Photon — This article is about the elementary particle of light. For other uses, see Photon (disambiguation). Photon Photons emitted in a coherent beam from a laser Composition Elementary particle …
18Pluto — This article is about the dwarf planet. For other uses, see Pluto (disambiguation). Pluto   …
19cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
20South America — South American. a continent in the S part of the Western Hemisphere. 271,000,000; ab. 6,900,000 sq. mi. (17,871,000 sq. km). * * * Continent, Western Hemisphere. The world s fourth largest continent, it is bounded by the Caribbean Sea to the… …
