Answer:
carbon, hydrogen, nitrogen and oxygen 
Explanation:
mostly, combination of carboxylic and amine groups
 
        
             
        
        
        
Answer:
because you don't get soil like you get the Sun rays everyday. It takes millions of years for formation of soil and you can't get it within the lifespan of one human. Hence it is considered as Non-Renewable resource.
Explanation:
 
        
                    
             
        
        
        
I know this isn't answering your question but i think you will find it useful to visit the link pasted below. i just visited it and it explains pretty much everything about this.
        
             
        
        
        
It is called peristalsis movement.