Complex sentence: The Prix des Chênes is a Group 3 flat horse race in France for two-year-old thoroughbred colts and geldings run over a distance of 1,600 metres (approximately 1 mile) at Longchamp Racecourse in September.
Split into simpler sentences: The Prix des Chênes is a Group 3 flat horse race in France for two-year-old thoroughbred colts and geldings. It is run over a distance of 1,600 metres (approximately 1 mile) at Longchamp Racecourse in September.