You are presented with the quiz "the gravitational pull of the Moon on Earth's oceans pumps what into the oceans?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the gravitational pull of the Moon on Earth 's oceans causes the tides" and "energy is pumped into the ocean by the winds and tides". 

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


 

     energy      