Complex sentence: The Hong Kong Cup is a Group 1 flat horse race in Hong Kong for three-year-old and above throughbreds run over a distance of 2,000 metres (approximately 1 mile 2 furlongs) at Sha Tin Racecourse in mid December.
Split into simpler sentences: The Hong Kong Cup is a Group 1 flat horse race in Hong Kong open to thoroughbreds which are three-years-old or above. It is run over a distance of 2,000 metres (approximately 1¼ miles) at Sha Tin Racecourse, and it takes place annually, presently in mid December.