Complex sentence: During the Fraternity's Centennial celebration in October 1998, a memorial service was held at Mills' gravesite, utilizing a format based on a ceremony used to dedicate Mills' monument which was placed in 1928.
Split into simpler sentences: During the Fraternity's Centennial celebration in October 1998, a memorial service was held at Mills' gravesite. The service was based on a ceremony used to dedicate Mills' monument which was placed in 1928.