Answer:
Free nitrogen is simply molecular nitrogen (N2). Nitrogen, in its molecular form, consists of two nitrogen atoms bound together with a tripple bond. ... So basically, any nitrogen that is in an organic compound is considered “fixed” nitrogen and N2 is considered to be “free” nitrogen
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Answer:
according to me butter is not a oil. But its good to have it as it is formed from milk!
 
        
             
        
        
        
Answer:
<h2>Exaptation</h2>
Explanation:
Exaptation is the process by <u><em>which the features acquire those functions for which they were not originally selected</em></u> or adapted. Feather is an example of exaptation, it has appeared in various fossils of the flightless ancestors of modern birds, it later became important for flying, Once they molded for flying it adapted for that function, It is found in both behavior and anatomy. 
 
        
             
        
        
        
Answer: Line graphs are used to track changes over short and long periods of time. When smaller changes exist, line graphs are better to use than bar graphs. Line graphs can also be used to compare changes over the same period of time for more than one group.
Explanation: