Content extract: it is an extract of the main content of the article, which requires short, precise and comprehensive. Format: in front of the content, occupying one page.

Keywords are selected from the title, abstract and text of the paper, which are words with substantial meaning to express the central content of the paper. Keywords are words used by computer systems to index the content characteristics of papers, which are convenient for information systems to collect and provide readers with retrieval. Generally, 3-8 words are selected as keywords for each paper, and a new line is set at the bottom left of the "abstract".