It's empty or fairly large, making the sounds from your hands bounce of the walls and therefore having it echo
        
                    
             
        
        
        
Answer: C. there is more silicon than calcium at the surface of the earth
Explanation:
 
        
             
        
        
        
Answer:
a. hydroxyle in tyrosine
b. 3' OH 
Request: Please mark me as the Brainliest. 
 
        
             
        
        
        
<span>Science is always changing and never completely proves anything because </span>uncertainty <span>is part of the scientific process
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Because we have been to busy trying to explore new areas rather than our own and were probably to scared to know what's in our planet so it doesn't cause panic