instruction:
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.
question:
Fact: Earth's magnetic patterns are used for finding locations of birds and fish. 
Question: what is Earth's magnetic patterns used for finding the locations of?
answer:
birds and fish.


question:
Fact: penguins are endothermic tetrapod vertebrates. 
Question: what are endothermic tetrapod vertebrates?
answer:
penguins.


question:
Fact: viruses cause death. 
Question: what can cause death?
answer:

viruses.