Answer: B. all the nitrogen obtained by animals come from plants. 
Explanation:
Animals are unable to use inorganic bacteria until plants absorb it and then animals get it from the plants so in effect, all the nitrogen obtained by animals comes from plants. 
Plants absorb nitrogen in the form of Nitrates which were fixed by bacteria from Nitrites which were further fixed from Ammonium which was fixed from atmospheric Nitrogen all by bacteria. 
 
        
             
        
        
        
Answer: it’s d preindustrial 
Explanation:
I just took it 
 
        
             
        
        
        
Answer:
A
Photosynthesis is one of the final steps in cellular respiration.
Photosynthesis provides the materials needed for cellular respiration
Explanation:
 
        
                    
             
        
        
        
Answer:
Option 2, or B: a way of classifying books
Explanation:
Dewey Decimal system definition = The Dewey Decimal Classification (DDC), colloquially the Dewey Decimal System, is a proprietary library classification system first published in the United States by Melvil Dewey in 1876.
What is the Dewey Decimal system? Well, the definition says it is a proprietary library classification system.
So..
Our answer is 2 or B: a way of classifying books.
Hope this helps!
- Melanie
 
        
             
        
        
        
Inhaling through the nose