Don't Forget to Floss
Yankel is in Dr. Goldstein's dentist's chair. "Now open your mouth wide, please," says Dr. Goldstein.
Yankel does what he's told. Dr. Goldstein looks inside Yankel's mouth and says, "Oy gevult, that's the biggest cavity I've seen in years! Oy gevult, that's the biggest cavity I've seen in years!"
"I heard the bad news the first time," says Yankel, gloomily, "there was no need to repeat yourself."
"I didn't repeat myself," says Dr. Goldstein with a smile. "That was an echo."