The annual college entrance examination kicked off on June 7th. When candidates sit in the examination room and receive the test paper handed over by the invigilator, have they ever been curious about what extraordinary "journey" such a crucial test paper went through before it was finally delivered to them? Proposition, printing, transportation, storage... Behind each link lies the hard work of the participants, as well as the special technological power that enables each college entrance examination paper to be delivered to the hands of the candidates without fail. The "mysterious" proposer will start selecting candidates about 2 months before the college entrance examination, usually consisting of university and middle school teachers. This process is called "entrance examination". The relevant departments will conduct a comprehensive review of the selected proposers, strengthen confidentiality education, and sign confidentiality agreements. During the college entrance examination proposition period, the proposer is not allowed to use any communication devices and can only contact external parties through fixed telephone, and the call content will be monitored throughout the process. Even if the proposer luckily brings communication devices into the venue, the signal blocking devices installed everywhere in the venue will still prevent the normal use of mobile phones and other devices. After the preliminary formation of the college entrance examination paper, it still needs to undergo repeated experiments and checks by experts until all opinions are unified and there are no longer any differences, and the college entrance examination paper is considered final. In this process, the proposer not only needs to rack their brains during the proposition process, but also compares the completed questions with the exercises in the exercise books on the market to prevent duplicate questions from appearing. After the proposition work is completed, the proposer cannot leave the proposition venue, but must wait until the end of the college entrance examination. Only when all candidates leave the examination venue can they leave. Even if they leave, according to regulations, staff members who participate in the proposition may not participate in the writing and publication of guidance books and materials related to the college entrance examination for a certain period of time without the permission of the examination authority. The garbage and sewage in printing units are strictly controlled. During the college entrance examination season, news about the printing of college entrance examination papers in prisons always arouses everyone's curiosity, which is not unfounded. Units that can print college entrance examination papers must have the qualification to print national secret carriers jointly issued by the Ministry of Education and the National Security Bureau, and prisons are indeed among them. In the "Notice on Further Strengthening the Confidentiality Management of National Unified Examinations", it is clearly stated that "prison printing factories that meet the confidentiality requirements for printing exam papers after examination can be issued a limited license scope" National Secret Carrier Reproduction License ", and the license scope column should indicate the words" only limited to printing exam papers ". Therefore, as long as certain conditions are met, prisons can become printing units for college entrance examination papers. In addition to prisons, units responsible for the printing of college entrance examination papers generally carry out fully enclosed management one month before the college entrance examination. Each workshop is equipped with comprehensive access control, monitoring, and anti-theft systems, and security personnel are on duty 24 hours a day. Even sewage pipes are equipped with protective nets. Workers who directly come into contact with test papers should also undergo closed management. The level of management rigor is similar to that of the proposer. To prevent missing questions, all the garbage they generate must be crushed before being transported out of the printing unit. Similarly, they also need to regain their "freedom" after the college entrance examination. Real time monitoring of the transportation process After the printing of the college entrance examination paper