Well, right away I know that it is some sort of mutualistic relationship. Since this is not an option here, my best guesses are either <em>B or C.</em>
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Please let me know if I was right :)
 
        
                    
             
        
        
        
Question 1) Photesphere 
Question 2) core 
Question 3) The suns gravity keeps them in place 
Question 4) True 
I'm not 100% about question 1 it's either photesphere or core, but I think Photesphere is correct
 
        
             
        
        
        
Answer:
The answer is number 4. asI think
 
        
             
        
        
        
A layer of smooth cartilage at their ends, which cushions the bones and prevents them from rubbing directly against one another. The whole joint is also enclosed in a synovial capsule, which is full of synovial fluid. The synovial fluid acts like the oil in an engine, lubricating the joint and preventing the cartilage from becoming worn down.
        
                    
             
        
        
        
Scientists collect information that allows them to make evolutionary connections between organisms. Similar to detective work, scientists must use evidence to uncover the facts. In the case of phylogeny, evolutionary investigations focus on two types of evidence: morphologic (form and function) and genetic.