<span>The person needs to report black stools that are tarry. These stools are an indication that there is bleeding. This occurs when digested blood gets in the stool. The stool will smell harshly. A person with a peptic ulcer must report this type of stool immediately.</span>
        
             
        
        
        
You should only test one variable/factor in a science experiment.
        
                    
             
        
        
        
Answer:
A single organism can adapt to a cold environment by growing long hair. 
Explanation: