Why Does an Astronaut Need a Spacesuit?
Why Does an Astronaut Need a Spacesuit? A spacesuit enables an astronaut to survive by providing him artificially with conditions like those he is used to on Earth....
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Who Invented the Jet Engine?
Who Invented the Jet Engine? The first flight by a jet-propelled aircraft was made in Germany on august 27, 1939. Its engine was designed by Hans-Joachim von Ohain, who...
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What Is a Meteorite?
What Is a Meteorite? Meteorites begin as bodies of matter traveling at great speed through space. In the solar system there are numberless such bodies, usually chunks...
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When Do Plants Breathe?
When Do Plants Breathe? Technically, plants don’t breathe. But plants do respire. Like animals, they use oxygen in the process of breaking down carbohydrates, and use...
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What Is Photosynthesis?
What Is Photosynthesis? Photosynthesis is the process by which green plants make food for themselves-and, indirectly, for all animals, including human beings. In...
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