1, echo before and after can make the articles seamlessly connected, make the articles more prominent and coordinate; Can make the article related internally; Can make the article match the connection; Can make the article echo before and after; You can let the article read the beginning and the end.

2. The echo before and after makes the content of the article complete and the structure rigorous, which enhances the realism and appeal of the article, thus better expressing the center of the article, but it is conducive to the expression of specific content.