Reconstruction of copyright protection system in the internet era Construction of legal protection system for the virtual property Guide to copyright protection in the metaverse era Transformation and innovation of copyright system in the internet era Research on the mode of copyright protection in the digital network era Study of construction of modern economic system in the new era New construction of library information services in the digital era reconstruction of market governance patterns in the digital economy era 并列题名：Transformation and innovation of copyright system in the internet era Research on the construction of personal information protection system in the era of big data