Answer: Regulate the movement of materials in and out of the cell 
Explanation:
The cell membrane of animal cells is a thin membrane that lines the entire cell surface, and it is a selectively permeable membrane, thus, allowing the entry of useful materials into the cell and exit of waste products out of the cell.
 
        
                    
             
        
        
        
Classical biotechnology dates back about 100, 000 years ago.
        
                    
             
        
        
        
It is B and I know it because I am in college and I already know about this question so your welcome for helping put
        
             
        
        
        
<span>A. endoskeleton
</span>Endoskeleton is not a characteristic of Arthropods that has attributed to their diversity and success. Endoskeleton is defined as inner characteristics of the skeletal feature of an organisms such as bears, humans, fish and etc.
Exoskeleton on the other hand is the trait by which arthropods posses. It is skeletal feature that is described outside or is extrinsic, this is evident as crabs have their skeletons outside of their body. 
        
             
        
        
        
6-C (breaks off)
7-C(they secrete acid that breaks away rocks)