 Complete the following phrase:  Christopher Knierim born November 5, 1987 is an American former pair skater. With his wife, Alexa Scimeca Knierim, he is a 2018 Olympic bronze medalist in the figure skating team event, a two-time Four Continents medalist 2016 silver, 2014 bronze, a three-time Grand Prix medalist, and a three-time U.S. National Champion 