Energy and matter characterize both physical and biological systems. These systems are defined both by the types of energy and matter they contain and by how that matter and energy move through and between systems. ... This means that energy and matter can change forms but cannot be created or destroyed.
        
                    
             
        
        
        
Unlike freshwater fish, saltwater fish <span>often contain a lower concentration of salt than the water they live in.
so your answer is </span><span>A. often contain a lower concentration of salt than the water they live in.
hope that helps!!!!!</span> 
        
             
        
        
        
Answer:
A
Explanation:
ice's density is lower that water's density