Sixth-grade science teacher, Mrs. Parks, asked her class, "Which human body part increases 10 times its size when stimulated?

No one answered until Mary stood up and said, "You should not be asking sixth-graders a question like that! I'm going to tell my parents, they will tell the principal, and he will fire you!"

Mrs. Parks ignored her and asked the question again, "Which body part increases 10 times its size when stimulated?" Mary's mouth fell open, "Boy, she is going to get in big trouble!"

Mrs. Parks ignored her and continued, "Anyone?" Finally, Billy stood up, looked around nervously, and said, "The body part that increases 10 times its size when stimulated is the pupil of the eye."

Mrs. Parks said, "Very good Billy."

She then turned to Mary and said, "As for you young lady, I have three things to say:

One, you didn't read your homework.

Two, you have a dirty mind.

And three, one day you are going to be very, very disappointed."