Complex sentence: Harry Prowell A.A. (10 July 1936--27 June 2000) was a Guyanese long distance runner who represented Guyana in the Marathon at the 1968 Summer Olympics in Mexico City, Mexico and known to be one of the greatest Marathon runners Guyana has ever produced.
Split into simpler sentences: Harry Prowell A.A. (10 July 1936--27 June 2000) was a Guyanese long distance runner who represented Guyana in the Marathon at the 1968 Summer Olympics in Mexico City, Mexico. He is known to be one of the greatest Marathon runners Guyana has ever produced.