Copyeditor moment: At the top of the ninth slide, it says “8 of 9″ instead of “9 of 9″.
Teeth are totally for biting! Just not for biting other people. And feet are totally for kicking! Kicking balls out on the playground or yard, not shins of your friends. Or balls of your friends for that matter, if you know what I mean, and I think you do (certainly if you have the XY thing going on).