Complex sentence: Hingham Middle School is the only public school in Hingham, Massachusetts for three educational grades, 6-8, formed by the merger of South and Central Junior High Schools in the 1990s.
Split into simpler sentences: Hingham Middle School is the only public school in Hingham, Massachusetts, serving three educational grades, 6-8. The school was formed by the merger of South and Central Junior High Schools in the 1990s.