You are presented with the quiz "What are coral reefs home to?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "sponges are a source of food for many species of fish" and "coral reefs are homes to thousands of different kinds of fish, sponges, algae, and mollusks". 

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


 

  fish         