Ключевые слова: 2017, action, athlete, atp, ball, best, billie, center, champion, championship, conference, court, example, exercise, federer, flushing, grand, hard, jean, king, loss, national, new york, open, players, points, practice, press, prize, professional, racket, roger, roger federer, serve, set, singles, slam, speed, sports, stadium, strings, swiss, switzerland, tennis, title, tournament, training, us, winner, workout,