(1) Typical theme, overall view. "Narration" is a typical theme, and "comment" is a global view, which makes the discussion more specific and easier to understand.
(2) The reason is based on the reason. The narration of facts paved the way for the emergence of "theory"
(3) Borrow people's words to increase the authority of comments. Journalists can comment directly, but the words of relevant authorities will make the speech more powerful and objective.
(4) The exposition should be incisive, the viewpoint should be correct and profound, and the narration and evaluation should be harmonious and natural.