Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Q: Spring tides are created when the sun and moon's tides match.

A: Which type of tides are created when the sun and moon's tides match?
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Q: You call egg-shaped galaxies, which are reddish to yellowish in color because they contain mostly old stars, elliptical galaxies.

A: What do you call egg-shaped galaxies, which are reddish to yellowish in color because they contain mostly old stars?
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Q: Gravity makes soil and rock particles move gradually down the slope during each thaw.

A:
What makes soil and rock particles move gradually down the slope during each thaw?
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