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?"

Fact: muscle contraction occurs when a diagonally oriented part of muscle gets shorter.
muscle contraction occurs when a diagonally oriented part of muscle gets what?

Fact: trucks are used for travel.
What are trucks used for?

Fact: hormones control many cell activities and are important in the chemical equilibrium of the body.

hormones control many cell activities and are important to what?