Complex sentence: Masako Chiba (born 18 July 1976) is a Japanese long-distance runner, who won the bronze medal in 10,000 metres at the 1997 World Championships in Athens and in the marathon race at the 2003 World Championships in Paris.
Split into simpler sentences: Masako Chiba (born 18 July 1976) is a Japanese long-distance runner. She won the bronze medal in 10,000 metres at the 1997 World Championships in Athens and in the marathon race at the 2003 World Championships in Paris.