Answer:
Liquids have an indefinite shape, while solids have a definite shape.
 
        
             
        
        
        
Thermocline - <span>a steep temperature gradient in a body of water, that is marked by a layer above and below at which the water is at different temperatures.
halocline - </span><span> a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water.
pycnocline - </span><span>a layer in an ocean or other body of water in which water density increases rapidly with depth.</span>
        
             
        
        
        
Answer:
c.building immunity towards diseases
 
        
             
        
        
        
Answer:
They use them so that they can see what type of organisms live there. 
Explanation: