Complex sentence: Rex is a census-designated place (CDP) located in Robeson County, North Carolina, U.S., at the 2000 census the population was 55 and ranked 4th on the list of the highest-income places in the United States.
Split into simpler sentences: Rex is a census-designated place located in Robeson County, North Carolina. As of the 2000 census, the CDP had a total population of 55 and ranked 4th on the list of the highest-income places in the United States.