Complex sentence: A typical Liangzhu community, of which there are over 300 found so far, chose to live near rivers, and boats and oars recovered indicate proficiency with boats and watercrafts.
Split into simpler sentences: A typical Liangzhu community, of which there are over 300 found so far, chose to live near rivers. There have been boats and oars recovered which indicate proficiency with boats and watercrafts.