Ключевые слова: 2018, argentina, athlete, backhand, ball, billie, center, championship, competition, court, del potro, example, flushing, forehand, game, grand, hard, jean, juan martin del potro, king, match, national, net, new, nike, ny, nyc, open, player, points, practice, professional, racket, set, singles, slam, sport, sports, stadium, tennis, tournament, training, us, us open, volley, york,