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

Q: Multiple genes mutations is usually necessary to develop cancer.

A: What is usually necessary to develop cancer?
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Q: Carbon dioxide is an example of a material that easily undergoes sublimation.

A: Carbon dioxide is an example of a material that easily undergoes what?
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Q: Cations are formed by the loss of one or two electrons from an element.

A:
What are formed by the loss of one or two electrons from an element?
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