Answer:
Ventilation and mixing outdoor air with indoor air
Explanation:
 
        
             
        
        
        
73130-26,  S62.323A, W51.XXXA, Y93.61 that should help.
 
        
             
        
        
        
Hello
It is because ur mouth is a dark and warm place which is the perfect environment for bacteria to grow and survive. It doesn’t matter if u brush it really well on ur tounge there and groves in ur tounge where the toothbrush bristles cannot reach and clean so that is where the bacteria lives. 
Hope this helps 
Plz mark me as Brainliest
        
                    
             
        
        
        
This is true. Hope this helps.
        
                    
             
        
        
        
Answer:
False
Explanation:
Almost all coal that is used today has its origins in the Carboniferous period. The Carboniferous period was a warm and wet one, with the majority of the land being swampy and covered with dense rainforests of ancient tree species. By the end of this period, the climate quickly changed, resulting int he collapse of the rainforests. As the trees were dying out, they were falling in the swamps, quickly being covered by the mud, so remaining largely preserved. Over time they got exposed to higher pressure and temperatures as they were getting deeper into the crust, eventually resulting in the formation of the coal.