Question: How many years did Michael Dante DiMartino work for an American animation studio owned by Waterman Entertainment?
Sentence (from "Avatar: The Last Airbender (season 3)"): Season Three (Book Three: Fire) of "", an American animated television series on Nickelodeon, first aired its 21 episodes from September 21, 2007 to July 19, 2008.
Relevant evidence: No