Which is the most likely reason the author used the word fresh so often in the passage

Can you provide the passage? If not, he word fresh in literature is most likely used to talk about something new or done again. For example, every morning you have a fresh start because in a way the day is 'reset'. Essentially you're staring from square 1. It can also mean something new because when you open a box that's never been opened it's fresh and new. It can also mean fresh as in no additives. For example there is a fruit and veggie section at the store but one half says 'organic' and the other does not. This is because one most sprayed with bug repellent and the other was not. So fresh can mean a lot in literature but you really have to use context clues to understand the full meaning.