I always loved that one. Brilliant.
“Scientific Progress Goes Boink” is the name of one of his books of comics if I remember correctly. I have them all. Time to get them back out.
Classroom Comebacks That Deserve Extra Credit 
During one particularly snarky lesson, the teacher looked around and said,
“If there are any idiots in the room, would they please stand up?”
The room went dead silent… until a lone freshman slowly got to his feet.
The teacher, startled, asked,
“You think you’re an idiot?”
The student shrugged.
“Not really. I just didn’t want you standing all by yourself.”
After a lecture on mental health, the psychology teacher posed a question:
“How would you diagnose someone who paces, shouts one minute, then weeps the next?”
A voice from the back called out,
“Sounds like our basketball coach on game day.”
In earth science, the teacher was explaining map coordinates.
“If I said to meet me for lunch at 23 degrees, 4 minutes north and 45 degrees, 15 minutes east, where would that be?”
After a moment of awkward silence, a student muttered,
“Probably having lunch alone.”
The physics teacher announced,
“Isaac Newton discovered gravity when an apple hit him on the head while sitting under a tree. Isn’t that incredible?”
One student nodded and said,
“Yeah, but if he had been trapped in a classroom like us, he probably wouldn’t have discovered anything.”
Teacher: “Why are you late, Joseph?”
Joseph: “There was a sign on the road.”
Teacher: “What sign?”
Joseph: “It said, ‘SCHOOL AHEAD — GO SLOW.’ So I did.”
Moral of the story:
Be careful what you ask your students. You might get more honesty than you bargained for. 
The hyphen problem…
‘THAT’S A CROC!’----(had to be said!, HAD TO!)
a biting remark indeed
I’ll quit now, it’s getting too long in the tooth
That’s why you have to develop a thick skin
‘I GOT NUTHIN’ ! GRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR!