Task: Explanation
Input (English): Question: Carol is building a small rocket to test in her back yard and, after much consideration, decides to use a biofuel to power her rocket. She tells her friends it's because it will create _____ carbon dioxide than fossil fuels. 
 Answer: less
Output (English): The advantage to biofuels is that they burn more cleanly than fossil fuels. As a result, they create less pollution and less carbon dioxide.