Sentences that highlight the characteristics of objects and reflect the characteristics of things, sentences that show the author's views or opinions in argumentative essays (or sentences that show sub-arguments), and lyrical sentences that are discussed after narration in narrative texts.
Key paragraphs refer to the first paragraph, the last paragraph, the transition paragraph, the paragraphs describing the environment or scenery, and other paragraphs that echo, compare or supplement the main content of the article.