You are presented with the quiz "Unequal heating of Earth 's surface by what causes polar easterlies?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "unequal heating of Earth 's surface by the Sun causes global wind patterns" and "another major type of wind is called a polar easterly". 

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


 

 sun          