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: Water must not be polluted to be safe. 
Question: What can happen to water to make it unsafe?
answer:
Pollution.


question:
Fact: animals have many organelles. 
Question: what have many organelles?
answer:
animals.


question:
Fact: Change from one species to another is evolution over geologic time above the level of the species. 
Question: What occurs over geologic time above the level of the species.?
answer:

Species changing to another.