Complex sentence: The Andros Barrier Reef is the world's third longest after Australia's Great Barrier Reef and the Central American Belize Barrier Reef, runs for 142 miles (225 km) averaging a distance of only 1--2 miles from the Andros shore.
Split into simpler sentences: The Andros Barrier Reef is the world's third longest after Australia's Great Barrier Reef and the Central American Belize Barrier Reef. It runs for 142 miles (225 km), averaging a distance of 1--2 miles from the Andros shore.