Task: Sentence Ordering
Input (English): Steps: (1) Acid rain makes waters acidic (2) Causes them to absorb aluminum from soil (3) Fish and their eggs die (4) Frogs and plants die (5) Insects and other wildlife die (6) The ecosystem is out of balance, causing further problems  
Where does the following step fit into the given list of steps: The water runs off from the soil into lakes, streams, etc 
Output (English):  After step 2.