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

Q: If a substance has a ph value greater than 7,that indicates that it is base.

A: If a substance has a ph value greater than 7, what does it indicate?
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Q: All life is built around the element carbon.

A: What element is all life built around?
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Q: Uranus is the least massive outer planet.

A:
Which is the least massive outer planet?
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