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.

[EX Q]: Fact: heat is detected by sensory nerve cells. 
Question: What is detected by sensory nerve cells?
[EX A]: heat.

[EX Q]: Fact: a seismograph can help predict earthquake damage. 
Question: What can a seismograph help predict?
[EX A]: Earthquake damage.

[EX Q]: Fact: black sand in the atmosphere decreases the temperature by blocking the sun. 
Question: what in the atmosphere causes the temperature to decrease by blocking the sun?
[EX A]:
black sand.