They produce narrow-band high-frequency sound to help them navigate in water. These high-frequency sounds are used in echolocation.  Echolocation is used to identify and locate prey and also avoid the predators. Marine mammals like whales and dolphin use echolocation in different manners.
        
             
        
        
        
Answer:
The volume of pollutants decrease in the ecosystem
 
        
                    
             
        
        
        
Answer:
all of the above
Explanation:
gravity makes a planet have a combination go straight yet go around the sun at the same time creating an ellipse
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