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.

Input: Consider Input: Fact: if a gas is heated the density decreases. 
Question: What happens to the density of a gas when heated?

Output: decreases.


Input: Consider Input: Fact: when an earthquake causes the ground to shake, this shaking can damage buildings. 
Question: How do earthquakes cause damage to buildings?

Output: The shaking of the ground causes damage to buildings.


Input: Consider Input: Fact: cats use saturated fatty acids to store energy. 
Question: What use saturated fatty acids to store energy?


Output: cats.