Answer:
A)Fixation. Nitrogen in its gaseous form (N2) can't be used by most living things
B) it can not be used because it most be converted or, ’fixed’  to a more useable form. To do this it goes through a process called fixation.fixation is the change in a gene pool from a situation where there exists at least two variants of a particular gene (allele) in a given population to a situation where only one of the alleles remains. 
C) This form can be made more usable if it’s converted. It has to go through the process of fixation so the gene pool changes. 
Explanation:
 
        
                    
             
        
        
        
Latin I think. It's like nomenclature, or something like that. ☺
        
             
        
        
        
Answer:B there were soon be insufficient food for the growing human populatio
 
        
             
        
        
        
<span>Sun Belt is the southern region of the United States, it includes Florida, Texas, Arizona, and California. P</span><span>eople moved south to avoid the freezing winters of the North. </span><span>
Movement into the "sun belt" is an example of the population movement - migration. </span>