You are presented with the quiz "Sleeping at night and working during the day is determined by what thing happening?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "aplanet rotating causes cycles of day and night on that planet" and "our bodies and senses adjust to the cycle of day and night so that we may work in the day and sleep at night". 

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


 

  planet rotating         