Complex sentence: The Prix Marcel Boussac is a Group 1 flat horse race in France for two-year-old thoroughbred fillies run over a distance of 1,600 metres (approximately 1 mile) at Longchamp Racecourse during the Prix de l'Arc de Triomphe meeting in early October.
Split into simpler sentences: The Prix Marcel Boussac is a Group 1 flat horse race in France for two-year-old thoroughbred fillies. It is run over a distance of 1,600 metres (approximately 1 mile) at Longchamp Racecourse during the Prix de l'Arc de Triomphe meeting in early October.