First-level title: the title number is "I", which is in bold type No.4, and the line is dedicated, and there is no punctuation at the end.
Second-level title: the title serial number is "(1)", which is the same as the font size of the text, the line is dedicated, and there is no punctuation at the end.
Third-level title: the title serial number is "1." It should be the same size and font as the text.
Fourth-level title: the title serial number is "(1)", which should be consistent with the font size and font of the text.
Fifth-level title: the title serial number "①" should be consistent with the font size and font of the text.
Matters needing attention in writing English titles:
Phrases are the main forms of English titles, especially noun phrases, that is, titles are basically composed of one or several nouns plus their prepositions and/or postattributes; The title of phrase type should determine the head word and then modify it before and after. The order of each word is very important, and improper word order will lead to inaccurate expression.
Generally don't use declarative sentences, because the title mainly plays a marking role, and declarative sentences are easy to make the title have judgmental semantics, which is not refined and eye-catching. In a few cases (critical, comprehensive and refuting), the question can be used as the title, because the question has an exploratory tone and is easy to arouse the reader's interest.