You are presented with the quiz "the gravitational pull of the Moon on Earth 's oceans causes water to what?" 

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 "tides are the rising and falling of ocean's water". 

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


 

    rise and fall       