Answer:
A
Explanation:
i go with A is that okay?
huh
 
        
             
        
        
        
Answer:
contractile vacuole
Explanation:
contractile vacuole is used for balance of water,salt etc
 
        
             
        
        
        
I think this is because the molecules in the rock are so small. The rock is also a solid.
        
             
        
        
        
Water temperature influences the onset of fish spawn, aquatic vegetation growth and the biological demand for oxygen in ponds. Temperature increases it holds less oxygen. Also water stratification.