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How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
What's going to happen on December 21st 2012? (Intermediate)
What color is each planet? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
How far is each planet from Earth? (Intermediate)
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