Answer:
The incorrect sentence is C. We should not buy grapes which scientists say are poisonous to dogs.
Explanation:
The commas should be placed like so,
We should not buy grapes which, scientists say, are poisonous to dogs.
I hope I helped! 
 
        
             
        
        
        
Answer:
the family getting their money at a great cost
 
        
                    
             
        
        
        
Answer:
A. Write detailed descriptions
Explanation:
I believe this is correct.
 
        
             
        
        
        
6 is b and 7 is c others i dont know