Which figure of speech is used in the bolded line in the following excerpt from this poem by robert frost?

nothing gold can stay

nature's first green is gold,
her hardest hue to hold.
her early leaf's a flower;
but only so an hour.
then leaf subsides to leaf.
so eden sank to grief,
so dawn goes down to day.
nothing gold can stay.

onomatopoeia

metaphor

personification

simile

her early leafs a flower is the bolded line

It was fifteen minutes before i could work myself up to go and humble myself to a ; but i done it, and i warn’t ever sorry for it afterwards, neither. i didn’t do him no more mean tricks, and i wouldn’t done that one if i’d a knowed it would make him feel that way. in at least one hundred words, describe what central theme in the adventures of huckleberry finn emerges in this excerpt, and how its emergence relates to the social norms of the time.