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?"

Input: Consider Input: Fact: a prism causes a rainbow.

Output: what does a prism form?


Input: Consider Input: Fact: muscle contraction occurs when a diagonally oriented part of muscle gets shorter.

Output: muscle contraction occurs when a diagonally oriented part of muscle gets what?


Input: Consider Input: Fact: treating H2O is used to remove harmful substances before drinking.


Output: Why do we generally treat H2O?


