Answer:
Proof you've done your time in school
An art-form and its colour-ful result.
I occur twice in eternity. And I'm always within sight.
What can be seen but not touched?
What kind of nail can be grown?
Two little holes in the side of a hill. Just as you come to the cherry-red mill.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?