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Radio waves have the longest wavelengths in the electromagnetic spectrum...
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The Earth began as a twinkle in the Solar Nebula's eye some 4.5 billion years ago...
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An ancient Greek mathematician, physicist, engineer, astronomer and philosopher...
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Parrots are birds of roughly 372 species found in most tropical and subtropical regions...
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The heart is an important organ that pumps blood throughout the body...
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Our Solar System is the Sun and everything that travels around it...
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Australia has a very dramatic landscape and is famous for its 'outback'...
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Is a ship accounted for as being one of the great maritime mysteries...
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Was the major technological, socioeconomic and cultural change...
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Optical instruments processes light waves to enhance an image...
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Human illnesses are caused by infection with disease-causing bacteria or viruses...
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A Myth is symbolic narrative, usually of unknown origin and at least partly traditional...
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Mexico is situated in the south-western part of mainland North America...
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The exact age of the Earth is unknown and is difficult to determine directly...
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The muscular system is composed of specialized cells called muscle fibers...
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Is a stretch of the Atlantic Ocean where ships and planes have disappeared...
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Was a civil war between the Northern and Southern States of America over trade issues...
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Crocodiles belong to the family of crocodilians, which include alligators, caimans and gavials...
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Is the world's third largest country in population and the fourth largest country in area...