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: Damming a river can cause something with fresh water to form. 
Question: What is the thing that is created by damming a river made of?
answer:
Fresh water.


question:
Fact: Ozone depletion increases the risk of getting skin cancer. 
Question: What increases the risk of getting skin cancer?
answer:
Ozone depletion.


question:
Fact: engines cause something to move. 
Question: what causes something to move?
answer:

engines.