Howard: Sheldon, why are you arguing with the DMV?
Sheldon: How else are they going to learn? Look, question 2, "When are roadways most slippery?" Now, okay, there are three answers, none of which are correct. The correct answer is, when covered by a film of liquid sufficient to reduce the coefficient of static friction between the tire and the road to essentially zero, but not so deep as to introduce a new source of friction.