You are presented with the quiz "A battery-powered computer requires a what for electricity to flow?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "powering an electrical device with a battery requires a path for electricity to flow through a closed circuit" and "electrical engineers work on power plants, computers, and other electrical devices". 

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


 

  closed circuit         