Answer:
Kidney
Explanation:
Nephron is the basic unit of structure in the kidney 
 
        
                    
             
        
        
        
Answer:
Commensalism
Explanation:
Commensalism is when one organism benefits and the other doesn't benefit and is also not harmed. The tree is helping the orchid and the orchid isn't benefiting or harming the tree.
 
        
             
        
        
        
Answer: continental glacier
Explanation:
These glaciers are very big and they can cover large amounts of land. These can also cover very large islands. Continental glaciers are the answer.
 
        
                    
             
        
        
        
A. Osmosis is the answer for this question