the answer would have to be Democritus 
 
        
             
        
        
        
Answer:
Considering the boys' situation, the boys live in the rural areas of one of the western United States, e.g. California.
Explanation:
Hantavirus is spread by rodents and is most common in rural areas of the western United States during the spring and summer months.  Hantavirus pulmonary syndrome also occurs in South America (especially in Argentina, Chile, Uruguay, Paraguay, Brazil, and Bolivia).  Hantavirus cases have also occurred in Canada and some parts of Asia, where they reportedly caused kidney disorders rather than lung problems.
 
        
             
        
        
        
<span>b.Eusthenpteron might be a common ancestor of bats and humans.
Hope this helps!
-Payshence xoxo</span>
        
             
        
        
        
Answer:
The scientific method
:
Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or prediction
Explanation
that's the scientific method but there are many example to how you use it in everyday life i.e the lights went out and you want to find out why, perhaps you didn't pay your bill or maybe the power went out.  then you would go through the steps to find out what happened
 
        
             
        
        
        
New disease that affects the younger of a population, shortage of availability of food, new competitor for food, new predator of jaguars (though there arent many of those)