Life and 98% of what you learn is a waste
        
                    
             
        
        
        
Answer:
Three Laws of Biology. “Social rules can be broken, but the laws of nature can't.”
A biological rule or biological law is a generalized law, principle, or rule of thumb formulated to describe patterns observed in living organisms. Many of these regularities of ecology and biogeography are named after the biologists who first described them.
 
        
                    
             
        
        
        
Answer:
OB) An elephant in the savannah develops without the ability to hear. A salamander living in a cave is born without, eyesight or fully developed eyes.
Explanation:
Adaptations are gradual modifications and changes in the physical characteristics or behavior of an organism, so that it could facilitate the survival of the organism in that particular environment. 
In case of elephant without ability to hear specially in the regions of Savannah where there is vast grasslands with scanty vegetation and animals, then the elephant can't hear any sound of danger like approaching calamities, also it could hear the call of other elephants, in case if the elephant becomes segregated. 
In salamander, low eyesight or low vision will further add to the misery, as there is already darkness in the cave. It could fall prey to any predator or it could not be able to feed on consumable organisms as it could see properly.
 
        
                    
             
        
        
        
Answer:
D 
Explanation:
Pls check the attachment,technical reasons
 
        
             
        
        
        
Circulatory System because it carries the blood throughout the body.