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

Q: Ovulation takes place in the ovary and is part of the menstrual cycle.

A: Ovulation takes place in what organ and is part of the menstrual cycle?
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Q: You call materials that have high resistance to electric current electric insulators.

A: What do you call materials that have high resistance to electric current?
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Q: Electromagnetic waves are created by oscillating charges.

A:
What are  electromagnetic waves created by?
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