Answer:
Topsoil is the part of a soil profile that is made up of partly weathered rock.
Hope this helps :)
 
        
                    
             
        
        
        
During the research Ambulocetus would be the first to consistently stay in water and Set over time they developed feet arms and <span>hands used to swim.</span>
        
             
        
        
        
Bone marrow contains stem cells that give rise to all of yur blood cells.
 
        
                    
             
        
        
        
Sea snails help to keep the algae's population from growing to high. And the algae provides the sea snails with energy from the snails eating it as a food source.
        
             
        
        
        
<span>The branch of
anatomy that focuses on body structures that are visible to the naked eye is
called gross anatomy. It is only concern with macroscopic details and therefore
do not need any aid of instrument. Gross anatomy is used to study dead bodies
that uses two approaches. The systemic approach, studied the different system
of the body while in regional approach, human body is  studied in different regions. </span>
<span> </span>