1, abstract or abstract, is an excerpt from the main content of the article, which should be short, concise and complete. The number of words can be as few as dozens, and it is advisable not to exceed 300 words.

2. Introduction, also known as preface, preface and introduction, is the main body of the paper and is only used at the beginning of the paper. The introduction should generally write the author's intention, explain the purpose and significance of the topic, and point out the scope of the paper writing. The introduction should be short and concise, and stick to the theme.

3. The abstract comes first, and the introduction comes last.