Answer:
Shark skin has been used by many cultures as sandpaper. It's kept shipmates safe in slippery-when-wet conditions. Swimsuits modeled on shark skin are said by Speedo to reduce drag by up to 4 percent. Now, research by two separate groups could lead to synthetic shark skin that would make ships and submarines faster and less expensive to operate.
 
        
             
        
        
        
Answer:
b is the correct answer ok bro
 
        
                    
             
        
        
        
Answer:
D)	a scientific journal about chemistry and a biography of a famous chemist
 
        
                    
             
        
        
        
Mitochondria, plastids and chloroplast all are surrounded by a double membrane
        
             
        
        
        
The answer is Complement 
this is for my Gradpoint fellas