COLORADO SPRINGS, COLORADO( Reuters)-Pale marble pavers crisscross the Terrazzo, the plaza at the heart of the U.S. Air Force Academy in Colorado that cadets traverse daily, on the way to class, the library and meals.... In their first year, cadets must run and keep to the narrow marble strips whenever they are on the 20-acre Terrazzo. Tusajigwe Owens doesn't take short cuts.... The graduation rate for Black cadets has for the last decade averaged 66%, compared to an overall graduation rate of