Preface has a pattern. Do you need two more spaces?

The introduction of the paper should be two spaces. The style template of the introduction is "Title 1", which is centered. You can also set the font style manually: bold, center and small font size. The text content format of the introduction needs to be indented in the first line of each paragraph, or it can be manually set to be indented in the first line of each paragraph, and the font should be Song typeface.