The Northern economy benefited from development in many of its industries, including textile and iron production. The war also stimulated the growth of railroads, improving transportation infrastructure.
        
             
        
        
        
Answer:
The title tells you what information the map is displaying. A Legend is used to explain symbols and colors on a map.
Explanation:
 
        
             
        
        
        
An implicit detail is a hint or seggestion.
        
                    
             
        
        
        
The research error described above is an example of selection bias. 
Selection bias takes place when, from a population of interest, a group of individuals is selected in order to construct a sample but without a proper randomization. The result is a sample which is not representative of the underlying population. 
According to the example, the target population of the research comprises all students but the sample only includes boys. Hence, selection has not been random because it followed a gender criteria, and the results obtained using it cannot be applicable to the whole population because they are affected by a selection bias. 
 
        
             
        
        
        
You have such nice writing, i like cursive writing :-)