Answer:
All this combination of reactions is summarized in that the bacteria reduced nitrate, that is, they added protons to said compound, giving nitrite as a product.
By promoting the appearance of nitrite and that it increases in its concentrations when the zinc dust is thrown away, it becomes reddish since there was a change in pH, that is, the medium was acidified.
Explanation:
Some bacteria take nitrate as a source and end up generating an oxide reduction reaction that gives nitrite as a product, if this reaction advances in a chain, that is, the nitrite is reduced after the nitrate, the product in the future would be ammonia
 
        
             
        
        
        
I’m not sure but I think A
        
                    
             
        
        
        
Explanation:
The atmosphere is the gaseous envelope round the earth. 
The biosphere is the part of the earth dominated and occupied by living organisms. 
As with other spheres of the earth, the biosphere and atmosphere are constantly interacting too. 
- Organisms breathe in air to their respiration processes. 
- Weather elements are conditioned by the atmosphere. 
- Decomposition of organisms release gases back into the atmosphere. 
learn more: 
Biogeochemical cycle brainly.com/question/4217448
#learnwithBrainly
 
        
             
        
        
        
Answer:
Because it is important to support the body to function properly