Answer:
C
Viruses need a host to survive.
Explanation:
 
        
             
        
        
        
In biology, the biotic factors pertain to the living components of Earth while the abiotic factors are those non-living chemicals and physical factors. The only choice that is not an interaction between biotic and abiotic factors is the third choice, "C. male elk fighting over a female". 
        
                    
             
        
        
        
Answer:
A.) a substance with ph between 0 and 7.
Explanation:
as acid has pH value between 0 to 7.
 
        
                    
             
        
        
        
Answer:
heat, density, boiling point
 
        
             
        
        
        
Answer:
blood because that is a part of your body bacteria