Answer:
they are being impacted negativily and this is what they are being impacted by industrial dumping, pesticides, and agricultiural fertilizer can end up in rivers, lakes, streams, etc.  
Explanation:
 
        
             
        
        
        
When reading questions, be careful not to read too quickly. In this case, fast but inefficient reading will lead us to assume that it is asking about ...
        
             
        
        
        
West Nile lead to a decline in susceptible avian and human hosts, with a subsequent decline in the number of cases since 1997
        
             
        
        
        
(C) earth's outer iron core
this is because iron is magnetic and therefore forms a strong magnetic field