You are presented with the quiz "What wets the skin, and when it evaporates, it cools the body?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "sweat wets the skin, and when it evaporates, it cools the body" and "sweat is made of salt and water". 

So, what's the best answer to the question?


 

  salt and water         