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parrot

(Encyclopedia)parrot, common name for members of the order Psittaciformes, comprising nearly 400 species of colorful birds, pantropical in distribution, including the parakeets. Parrots have large heads and short n...

wasp

(Encyclopedia)wasp, name applied to many winged insects of the order Hymenoptera, which also includes ants and bees. Most wasps are carnivorous, feeding on insects, grubs, or spiders. They have biting mouthparts, a...

pyramid, structure

(Encyclopedia)pyramid. The true pyramid exists only in Egypt and Sudan, though the term has also been applied to similar structures in other countries. Egyptian pyramids are square in plan and their triangular side...

bivalve

(Encyclopedia)CE5 Internal anatomy of a clam, Anodonta, representative mollusk of the class Pelecypoda (the bivalves) bivalve, aquatic mollusk of the class Pelecypoda (“hatchet-foot”) or Bivalvia, with a la...

solar system

(Encyclopedia)CE5 Solar system CE5 solar system, the sun and the surrounding planets, natural satellites, dwarf planets, asteroids, meteoroids, and comets that are bound by its gravity. The sun is by far the ...

camera

(Encyclopedia)CE5 Image formed by a camera camera, lightproof box or container, usually fitted with a lens, which gathers incoming light and concentrates it so that it can be directed toward the film (in an opt...

Chávez Frías, Hugo Rafael

(Encyclopedia)Chávez Frías, Hugo Rafael o͞oˈgō räfäĕlˈ chäˈvĕs frēˈäs [key], 1954–2013, Venezuelan political leader, president of Venezuela (1999–2013). Raised in poverty, he was educated at the ...

impressionism, in painting

(Encyclopedia)impressionism, in painting, late-19th-century French school that was generally characterized by the attempt to depict transitory visual impressions, often painted directly from nature, and by the use ...

molecular weight

(Encyclopedia)molecular weight, weight of a molecule of a substance expressed in atomic mass units (amu). The molecular weight may be calculated from the molecular formula of the substance; it is the sum of the ato...

metamorphism

(Encyclopedia)metamorphism, in geology, process of change in the structure, texture, or composition of rocks caused by agents of heat, deforming pressure, shearing stress, hot, chemically active fluids, or a combin...