Covalent bond? Carbon is usually the structure for a polymer Bc it can make up so many things including covalent bonds used to make polymers
        
             
        
        
        
It is located <span>midway on the anterior surface of the shell.</span>
        
             
        
        
        
Tobias drank from a contaminated water fountain
        
             
        
        
        
Answer:
Hope this helps :)
https://www.sciencedirect.com/topics/engineering/nitrogen-source
Think this is the website you're looking for 
Explanation:
 
        
                    
             
        
        
        
The reduced the change of that matter