Complex sentence: Ren Longyun (born 1987-10-12 in Minhe, Qinghai) is a Chinese athletics marathon runner, who will represent his country at the 2008 Summer Olympics.
Split into simpler sentences: Ren Longyun (born 12 October 1987 in Minhe, Qinghai) is a Chinese long-distance runner who specializes in the marathon. He will represent his country at the 2008 Summer Olympics.