During a research trip, Lisa learns that Sideshow Bob is the chief scientist at a big chemical engineering company; Marge tries to teach a teen church group about healthy sexual practices.
Dan Castellaneta
Homer Simpson / Abe Simpson / Barney Gumble / Krusty (voice)
Julie Kavner
Marge Simpson / Patty Bouvier / Selma Bouvier (voice)
Nancy Cartwright
Bart Simpson / Nelson Muntz / Ralph Wiggum (voice)
Yeardley Smith
Lisa Simpson (voice)
Hank Azaria
Moe Szyslak / Chief Wiggum / Apu / Comic Book Guy / Carl (voice)
Harry Shearer
Ned Flanders / Mr. Burns / Smithers / Skinner / Lenny (voice)
