this is how i would write it:
 volunteering can make a huge difference in a town.
 mayor lin said, “parks are clean due to volunteers”
 overall, community service strengthens a city.
        
             
        
        
        
For r number 3 find a pattern between all the numbers
For the other one I would say that the planet can’t be seen since the number of years is not near 1 therefore it’s not rational. 
These are my hypothesis!
 
        
             
        
        
        
Answer:
I think we have to put comma and full stop at right places
My sister Amy, my friend Kyle, and I went to the park.