You are presented with the quiz "Deep burrowing earthworms do what to the looseness of soil for root growth?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the looseness of soil has a positive impact on a plant 's roots' growth in that soil" and "deep burrowing earthworms improve soil porosity, water movement and plant root growth". 

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


 

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