hope this helps 
I do think that they close to not allow too much of either water or air from entering. 
the hollow tube allows water to flow easily.
https://www.bbc.co.uk/bitesize/guides/z28g7p3/revision/1
 
        
             
        
        
        
Hello,
Your answer would be:
D.	stalactite; stalagmite
Plz mark me brainliest
        
             
        
        
        
Global warming is an issue to organisms or species because not all animals can adapt so certain living conditions. high human population growth rate drive further extinctions of plants and animals because humans need space to live so we cut down their habitats and they die. not all animals can adapt to certain living conditions.
        
             
        
        
        
I think it’s A the way u put this
        
                    
             
        
        
        
they have 3 fingers we have 5