<span>Studying the changes in densities of pocket gophers when large herbivores such as elk are excluded from mountain forests would be an example of studying ecology at the community level.
A community refers to a group of organisms of various species that live in the same location and interact with each other. So, if this scientist is observing gophers and elks, they are looking at the level of communities, not anything more or less.
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There are 5 levels of cell organization recognized by biologists.
        
                    
             
        
        
        
Answer:
Water
Explanation:
Its water because water has many forms and all those forms are being converted into other forms of water during the cycle
 
        
             
        
        
        
Ethanol is a biofuel, which can <span>be fermented from various sources, but in United States, most of Ethanol is made from "Corn"
In short, Your Answer would be Option A
Hope this helps!</span>