Complex sentence: There are already several large Asian supermarkets such as the Kam Man Foods and Super 88 supermarket chains, and other businesses that are competing with Boston's Chinatown; also, several businesses operating in Chinatown now have branches in Quincy.
Split into simpler sentences: There are already several large Asian supermarkets such as the Kam Man Foods and Super 88 supermarket chains, and other businesses that are competing with Boston's Chinatown. Several businesses operating in Chinatown now have branches in Quincy.