Complex sentence: She won a silver medal in the 10,000 metres at the 1990 Commonwealth Games in Auckland and in 1991, she broke the World Best for 10 miles, with 51:41 in New York.
Split into simpler sentences: She won a silver medal in the 10,000 metres at the 1990 Commonwealth Games in Auckland. In 1991, she broke the World Best for 10 miles, with 51:41 in New York.