D, active transport because that protein uses atp to cross channels and active transportation is the only form of movement that’s used atp to move
        
             
        
        
        
Answer:
3.)CATASTROPHISM
Explanation:
catastrophism suggested the features seen on the surface of earth such as mountains,were formed by large abrupt changes or catastrophes 
 
        
                    
             
        
        
        
Would it be its beak? It's hard and protective like scales
        
                    
             
        
        
        
There is a valve at the meeting point between each ureter and the bladder prevents the back flow of urine from the urinary bladder to the kidney
        
             
        
        
        
I would say the alveoli. They are tiny air pockets in the lungs: this is where the diffusion of oxygen and carbon dioxide occurs. 
Hope this helps! x