(Encyclopedia) hearing aid, device used in some forms of deafness to amplify sound before it reaches the auditory organs. Modern hearing aids are electronic. They contain a tiny receiver and a…
(Encyclopedia) thalidomidethalidomidethəlĭdˈəmĭdˌ [key], sleep-inducing drug found to produce skeletal defects in developing fetuses. The drug was marketed in Europe, especially in West Germany and…
(Encyclopedia) nitrogen mustard, any of various poisonous compounds originally developed for military use (see poison gas). Like mustard gas and lewisite, it is a vesicant (blistering agent). In the…
Family lifeHatching outNesting in coloniesBrooding OviraptorFossilized mother and eggsEver since dinosaurs were identified as reptiles, scientists have assumed that they laid eggs, in the same way…
(Encyclopedia) animism, belief in personalized, supernatural beings (or souls) that often inhabit ordinary animals and objects, governing their existence. British anthropologist Sir Edward Burnett…
by Dan Steckenberg The term "hero" is perhaps overused today, but these guys were the originals. The mythology of ancient Greece was filled with great heroes who slew monsters,…
(Encyclopedia) radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a…
(Encyclopedia)
CE5
A. Structure of a bird wing B. Structure of a bat wing
wings, flight organs of the bird, the bat, and the insect. Birds' wings are pectoral appendages that are basically the…
