Answer:
Co-vid-19
Explanation:
I think because since Co-vid-19 is new and nobody knows what the real side effects are, they really can't make any medicine for it. It will take time and if they do make medicine, it will take time to know how It will react and how it will react in the long term.
 
        
             
        
        
        
The answer would be Option D: more bone
        
                    
             
        
        
        
Answer:
The amount of people per square mile or kilometer of land; also called arithmetic density.