Answer:
3, abba bcbc
Step-by-step explanation:
Where are the songs I used to know (a)
Where are the notes I used to sing? (b)
I have forgotten everything (b)
I used to know so long ago; (a)
Summer has followed after Spring: (b)
Now Autumn is so shrunk and sere, (c)
I scarcely think a sadder thing (b)
Can be the Winter of my year. (c)
Hope this helps!