itinerary
2009-02-23 19:11
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科学60秒:存在钻石星球？
Imagine climbing diamond mountains, or hiking around the graphite shores of a lake of tar. Sound a little sci-fi? Well a new discovery suggests planets like that might be out there—planets with...
短文：科学理论
科学理论Scientific Theories In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture...
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