A boy kept disrupting his third grade class by breaking wind
loudly. This angered his teacher so she kept him after school and
demanded to know what prompted such offensive behavior.

He proudly explained,

"I do it because it's the one thing in the world I can do better
than anybody."

"That's what you think," said his teacher. "If I prove I can do
it better, will you stop doing it?"

Supremely confident he couldn't be outdone, the kid instantly
agreed.

The teacher then placed two sheets of paper on the floor and put
a little pile of chalk dust on each one.

The kid dropped his pants, squatted down, broke wind and blew all
but a smidgen of dust off his paper.

The teacher followed his example but when she was done, there
wasn't the slightest trace of dust left on her paper.

The boy was astonished, chagrined and asked if she would please
do it again. When she repeated the process, he peeked up under
her skirt, gasped and indignantly exclaimed,

"Wow, no wonder you won! You've got a double-barrel!"