Complex sentence: The Nell Gwyn Stakes is a Group 3 flat horse race in the United Kingdom for three-year-old thoroughbred fillies run over a straight distance of 7 furlongs (1,408 metres) at Newmarket's Rowley Mile course in mid April.
Split into simpler sentences: The Nell Gwyn Stakes is a Group 3 flat horse race in the United Kingdom for three-year-old thoroughbred fillies. It is run over a straight distance of 7 furlongs (1,408 metres) at Newmarket's Rowley Mile course in mid April.