~Hello there!
Your question: Which stores groundwater?
Your answer: Groundwater is stored by the aquifer.
Any queries ^?
Happy Studying!
        
             
        
        
        
Answer:
Acute
Explanation:
It only has angles less than 90°.
 
        
                    
             
        
        
        
Well, pollution is probably the main reason, but i think all of them are reasons why animals are dying off, if there isn't any choice for all of them, then your best bet would be to do a, pollution.