Marking requires not to mark the original author's works, or the title of the paper, the publication time of the original author and the page number every time. This is necessary. GB/T 77 14-2005 "Rules for the Description of References after Documents" clearly requires the format of references.

Not necessarily. It depends. If it is a well-known celebrity quotation, you don't need to indicate the source of the original words, otherwise you will mark it. When quoting documents, it is best to indicate the author, year, publishing house and page number.

At the end of the paper, the references are explained. In the list of references at the end of the article, all references should be sorted by Arabic numerals in the order in which they appear in the text. Be sure to number them in the order in which they appear in the text.