DUESSELDORF, Germany (AP)—Andy Roddick and Ryan Harrison lost singles matches Sunday, giving Argentina an unassailable 2-0 lead over the United States on the opening day of the Team World Cup. The eight-nation tournament on clay is a warmup for the French Open, which starts in one week. Roddick, playing his first tournament since March, lost to Carlos Berlocq 6-2, 6-2 in the Red Group.