Complex sentence: The Chiefs compete in the Greater Middlesex Conference (GMC), which is made up of private and public high schools located in the greater Middlesex County area and operates under the supervision of the New Jersey State Interscholastic Athletic Association (NJSIAA).
Split into simpler sentences: The Chiefs compete in the Greater Middlesex Conference (GMC), made up of private and public high schools located in the greater Middlesex County area. The league operates under the supervision of the New Jersey State Interscholastic Athletic Association (NJSIAA).