Answer:
Explanation:
It helps in assessing the level of pollution in relation to the air quality standards. Standards are a  measure to set the target for pollution reduction and achieve clean air. 
 
        
             
        
        
        
Answer:
I cant answer this entirely but I can tell you the definition
Explanation:
Working badly or unreliably because of imperfections.
mistaken or misleading because of flaws
having or displaying weaknesses.
Hope this helps a little bit
You didnt really give much information:)
 
        
             
        
        
        
I believe the answer would be A. Diffusion is  "the spreading of something more widely"  Which fits in with this. 
        
                    
             
        
        
        
Explanation:
Natural materials are those that are found in nature and have not been made by humans. By comparison, synthetic materials are man-made and cannot be found in nature. Synthetic products are usually created in laboratories by mixing different chemicals, or prepared compounds and substances made in a laboratory.
 
        
             
        
        
        
6 is french and african 7 is african catholism