Answer:
Ozone high in the atmosphere is a pollutant, but near Earth's surface, it provides protection from harmful rays.
Explanation:
I had this test last week so here you go, let me know if it helped! 
 
        
             
        
        
        
Answer: atomic mass is the amount of protons and neutrons
Explanation:
 
        
             
        
        
        
The fact that gravity exists as it can be repeatedly tested and verified