Complex sentence: The Racing Post Trophy is a Group 1 flat horse race in the United Kingdom for two-year-old thoroughbred colts and fillies run over a distance of 1 mile at Doncaster Racecourse in late October.
Split into simpler sentences: The Racing Post Trophy is a Group 1 flat horse race in the United Kingdom for two-year-old thoroughbred colts and fillies. It is run over a distance of 1 mile at Doncaster Racecourse in late October.