A nocturne is <span>a short composition of a romantic nature, typically for piano.
One of the best known composers are </span><span>Frédéric Chopin</span>
        
             
        
        
        
Answer:
120 eighth notes per minute.
Explanation:
The timing is a jig, (6/8 timing) meaning that there are 6 beats per measure and the 8th note gets one beat. 120 is the metronome speed, indicating that the piece must be played at the speed of 120 eighth notes per minute. 
Hope this helps!
 
        
             
        
        
        
Either B or C but I believe it is C
        
             
        
        
        
Answer:
more nitrogen gas became present in the atmosphere