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Gravity 重力 What happens if you drop a book? 如果你丢一本书会发生什么？ Absolutely, it will fall down to the floor. This is called gravity. 很显然，书会掉到地上。这就叫做重力。 Gravity pulls from the center of the Ea
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Orbit 轨道 Do you know what an orbit is? 你知道什么是轨道吗？ An orbit is the path of a planet when it moves around the sun. 轨道是行星围绕太阳运动的轨迹。 It is similar to a cycling track. 它类似于自行车赛道。 As
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The one thing that won't change in the future is Egypt's complete and art dependence on the Nile. So far Egypt has been able to discover all threaten other Nile state to prevent them tapping into the supply of Nile water. Most Egyptians believe it's
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The idea is to build five major ventilation corridors, running from northern suburban areas to the south. They would be created by connecting Beijing's parks, rivers, lakes, and highways along with the capital's green belts, and possibly also by limi
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Did you ever dream of digging a hole so deep it came out the other side of the earth? Let's play that game again, using a little physics. First we have to imagine that our tunnel is lined with super-heat-resistant material so we can pass through laye
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