Complex sentence: The school was built in 1963 and underwent major renovations in 1991 which added a new wing with state-of-the-art science labs, new guidance offices, and a small instructional theater.
Split into simpler sentences: The school was built in 1963 and underwent major renovations in 1991. These renovations added a new wing with state-of-the-art science labs, new guidance offices, and a small instructional theater.