Answer:
element and compund
Explanation:
an element is the most basic substance that cannot be decomposed into anything simpler 
an compound is a substance that is formed when two or more elements combine in constant ratio chemically
 
        
             
        
        
        
Answer:
water moves every time there is a wave.
Explanation:
i hope that helps
 
        
                    
             
        
        
        
Answer: the ecosystem is balanced.
Explanation: