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: Shrews generate the most heat by keeping their metabolic rate high. 
Question: What metabolic rate does a shrew have?

Answer: High rate.


Question: Fact: Some mollusks are not easily seen with the naked eye. 
Question: What are not easily seen with the naked eye?

Answer: mollusks.


Question: Fact: Motion is most efficient on a smooth, flat surface. 
Question: A smooth and flat surface is ideal for what?

Answer:
Motion.