The answer is stem cells. Normal stem cells and germ cells can also be said to be immortal
 
        
                    
             
        
        
        
Rate of reaction will increase with the presence of a catalyst.
This is due to catalysts providing an alternative reaction pathway with lowered activation energy required, allowing an increased rate of reaction.
        
             
        
        
        
Flash floods, hailstorms
hope this helped
        
             
        
        
        
They are constantly contributing to the scientific community and
improving it. There are always new things to be discovered and they are
constantly doing just that?