Answer:
recurrent, recurring, repeated, persistent, periodic, perennial, chronic, continuing, constant
They is referring to the reader
C.Frankenstein's detailed account of his emotions after creating the monster.
Romantic literature has this unique characteristic in which the focus goes to the narrator or the character emotions, describing an inner world that was often overlooked by previous authors. By going deep into Frankensteins emotions Mary Shelly gives the romantic characteristic to the story.
The first sentence is correct.
