Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

[EX Q]: Fact: Vertebrates are all chordates that have a spinal column. 
Question: What do all vertebrates have that invertebrates don't?
[EX A]: a spinal column.

[EX Q]: Fact: individual nerve cells transmit nerve impulses to other cells. 
Question: What transmit nerve impulses to other cells?
[EX A]: individual nerve cells.

[EX Q]: Fact: Puppies and kittens may have parasitic worms. 
Question: What might puppies and kitties have?
[EX A]:
parasitic worms.