传统纸质出版物大致为三类:书籍、报纸、期刊。这些出版物在发行时都有其最小的基本单元,如书籍、期刊以“本”为基本单位,报纸以“份”为单位。若读者想购买某本书的某几页,并只付这几页的款,这种购物就无法实现。同样,若读者只想购买某本期刊的某篇文章,某份报纸的某一版,并只 Traditional paper publications roughly three categories: books, newspapers, periodicals. At the time of publication, these publications have their smallest basic units, such as books, periodicals, “Ben” as the basic unit, and newspapers as the “unit”. If readers want to buy a few pages of a book, and pay only a few pages of this paragraph, this shopping can not be achieved. Similarly, if readers only want to buy an article in a journal, a particular edition of a newspaper, and only