Sharing and saving of scarce information are generally resources that are not available elsewhere or are difficult to find, have high thresholds, and are easily deleted and invalidated. . . Or the most complete summary of the entire network in previous years, please indicate the source when forwarding. For example, rare information such as Hong Kong and Taiwan/Republic of China/ancient books/used books, information not available in general places. The range of information in this channel is at the top # Material # Resources # Share # Sharing # Books # Learning # Secrets # Documents # E-books # Reading # Growth Improvement # Academic # Community # If you have any submission recommendations, sharing cooperation, constructive help, etc., you can Feixin Robot @flyletters_bot Friendly Link @tieliu