I believe it's B. That would be the best guess
        
             
        
        
        
Answer:
Recent studies have examined the possibility that variation in species richness within communities may influence productivity leading to an exploration of the relative effect of alterations in species number per se as contrasted to the addition of productive species. 
Explanation:
hope this helps
have a great day/night
 
        
             
        
        
        
Answer:
soluble molecules 
Explanation:
Soluble molecules dissolve completely when mixed with water, hence forming a solution 
 
        
                    
             
        
        
        
Answer:b. The earth has warmed 10 times faster than it did coming out of the last Ice Age
Explanation: global warming from environmental degredation.
 
        
             
        
        
        
Answer:
A few examples could be an increase in food, an increase in shelter, a decrease in predators, or more land.