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?"
--------
Question: Fact: Vertebrates have a complete digestive system and a closed circulatory system.

Answer: What do all vertebrates have?


Question: Fact: Experiments are often done where chemicals are prepared.

Answer: Experiments are often done where what?


Question: Fact: Agnathans are thought to have been the earliest vertebrates.

Answer:
What are Agnathans?