Guinea pigs should not be used as “guinea pigs”

From: 500 Keys
Season 22, Episode 21

Sandwiches should not contain sand

From: The Bart of War
Season 14, Episode 21

I should not be twenty-one by now

From: Simpsons Tall Tales
Season 12, Episode 21

Science class should not end in tragedy

From: Skinner’s Sense of Snow
Season 12, Episode 8