I believe this would be answered in a different subject, but luckily I know the answer! :D 
Greater, Lower would be your answer.
        
             
        
        
        
i would say false because if its a physical dictionary you can just look through the pages to find the word you are looking for. 
 
        
             
        
        
        
I need more info
But if u want definition 
Synonym mean related words
        
             
        
        
        
B- you choose your topic on based purpose. If you purpose is to educate your topic would be different then if you
want to entertain your audience.