It is bad to litter because that is harming the environment. When you throw out a can, it can harm a animal or several animals. Litter can also sink into the ground (I think) and harm the plants growing.
        
                    
             
        
        
        
B) A long time increase in the Earths Average temperature
        
                    
             
        
        
        
A model organisms is a species that has been widely studied, usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages. model organisms are non-human species that are used in the laboratory to help scientists understand biological processes. 
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First part is explaining second part is explaining the uses)
        
             
        
        
        
Answer:
아니 난 아니야
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