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: Aging is associated with apoptosis. 
Question: What stage is associated with apoptosis?
answer:
aging.


question:
Fact: You can navigate through the Pacific with a compass. 
Question: What can you use to navigate the Pacific?
answer:
compass.


question:
Fact: Sponges have specialized cells to pick up planktonic food to digest. 
Question: What does a sponge's specialized cell do when it picks up planktonic food?
answer:

Starts to digest.