Complex sentence: Afterward, when the nuns find trophies amid the dust and grime which reveal that the school had won the all-state choir championship before, sometimes for several consecutive years, Mary Robert wonders aloud whether they still hold the competition or not.
Split into simpler sentences: Afterward, when the nuns find trophies revealing the school had won the all-state choir championship before, sometimes for several consecutive years. Amid the dust and grime, Mary Robert wonders aloud whether they still hold the competition or not.