A teacher was giving a lesson on the circulation of the blood. Trying to make the matter clearer, she said,”Now class, if I stood on my head, the blood, as you know, would run into it, and I would turn red in the face.”
“Yes,” the class responded.
“then why is it that while I am standing upright in the ordinary position the blood doesn’t run into my feet?”
A little fellow in the back of the room shouted, “cause your feet ain’t empty!”
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