To refine the central idea of a passage, the paragraph should present examples or applications of the central idea of the passage.
To refine the ideas of a text, it is necessary to make those ideas more understandable to the reader. For this, it is necessary to present examples, data, and situations where this idea applies, allowing the reader to have a greater understanding of it.
As you didn't show the passage the question refers to. This makes it impossible for me to provide an exact answer, but I hope the above information can help you.
More information about the central idea of a text in the link:
https://brainly.com/question/1914191