Turn the given fact into a question by a simple rearrangement of words. This typically involves replacing some part of the given fact with a WH word. For example, replacing the subject of the provided fact with the word "what" can form a valid question. Don't be creative! You just need to rearrange the words to turn the fact into a question - easy! Don't just randomly remove a word from the given fact to form a question. Remember that your question must evaluate scientific understanding. Pick a word or a phrase in the given fact to be the correct answer, then make the rest of the question. You can also form a question without any WH words. For example, "A radio converts electricity into?"

Q: Fact: operating a car usually requires fossil fuels.

A: What requires fossil fuels?
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Q: Fact: a gas in the air condensing in clouds causes rain.

A: What condenses in clouds to cause rain?
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Q: Fact: sperm nuclei enter the egg.

A:
what enters the egg?
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