To steer her readers in the right direction to solve the crime, Agatha Christie repeats key words and similar words. She did this so that these words will be retained in the mind of a reader. If a person reads the word three times, it is already kept in one's own mind. She was popular for making mystery stories based on famous nursery rhymes and poetry.
old society refers to often ancient cultural practices and modern society referes to those practices that relate to the industrial mode of production or devlopment.
