Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered the evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time.
        
             
        
        
        
Answer:
Explanation:
Not sure about the first question but
#2: hybrid
#3: alleles
 
        
             
        
        
        
The air that we breathe in is an example of solid solution