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: When water reaches zero degrees Celsius, it expands.
What happens when water reaches zero degrees Celsius?

Fact: Pituitary hormones are controlled and produced in glands.
What type of hormones are produced and controlled in the glands?

Fact: Airplanes transport millions of humans move across bodies of water every year.

What transports millions of humans over water every year?