I was having trouble getting some 2nd graders to respect their teacher:
You know when a garbage collector comes down the street, do you think he wants to see all of the cans kicked over and the trash spilled all over the street? NO!! He wants to see all of them nicely lined up for his truck with the lids closed and the trash all inside the cans.
When your teacher comes to school, she wants to see all of you in nice straight lines with your mouths closed or if you are talking, you should be saying nice things to each other--not spewing garbage all over the room by using ugly words!