Complex sentence: Meanwhile, Megan lets Chad, Ralph, and Andy into the department store to scare the girls by rolling a bowling ball down the hallway; the girls then attempt to leave the store, but find themselves locked inside.
Split into simpler sentences: Meanwhile, Megan lets Chad, Ralph, and Andy into the department store to scare the girls. Chad and Ralph scare them by rolling a bowling ball down the hallway; the girls then attempt to leave the store, but find themselves locked inside.