You are presented with the quiz "Some precipitation that falls on land may soak in, becoming a breeding place for what?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "some precipitation that falls on land may soak into the ground, becoming groundwater" and "stagnant water is often a breeding ground for mosquitoes". 

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


 

 mosquitoes          