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: spread of disease is another potential threat in the environment.

A: spread of what is another potential threat in the environment?
****
Q: Fact: Ancestors of hagfish are thought to have unpaired, median fins.

A: Ancestors of hagfish are thought to have what fins?
****
Q: Fact: ethologists usually study observable behaviors in natural enviornments.

A:
Who studies observable behaviors in natural environments.?
****