Rainwater can replace or replenish freshwater sources.
Precipitation, such as rainwater, is the source of freshwater on Earth.
When the amount of surface freshwater increases, so does the amount of groundwater.
Human activity, such as taking a bath, may change the quality of a freshwater resource. :)
 
        
                    
             
        
        
        
Oxygen in the presence of sunlight
        
             
        
        
        
A genetic mutation is a permanent modification in the DNA sequence of a gene to what is found in most people.