Peking University can be said to be the highest institution of higher learning in China at present. Peking University was transformed from Shi Jing University Hall and founded in 1898. After the school was founded, I don't know when the audit system began. No matter who they are, they can freely enter the auditorium of Shi Jing University at that time and attend classes in any classroom as long as they pay two yuan. However, these people did not have their school status, school uniforms and diplomas at that time, and their only authority was to study on campus. Even so, there are still many masters in the audience, such as Shen Congwen, Zhou and Yang Mo.

When Mr. Cai Yuanpei went to Peking University as the president, the system of audited units had existed for a long time. At that time, the teacher who taught at Peking University told Mr. Cai Yuanpei that at that time, there were five openness to these audited units, namely, classroom openness, library openness, bathroom openness, playground openness and canteen openness, so for these audited units, it was no different from the formal students of Peking University. Moreover, during his tenure, Mr. Cai Yuanpei was very supportive of this auditor system and carried it forward to let more people who wanted to learn enter Peking University.

At that time, Peking University still had an auditor system. Eavesdropping students? For the audience, it needs to go through some related procedures, but for those? Eavesdropping students? Generally speaking, they go directly to the classroom without formalities. There were times when there were more than a dozen people in class and only one person in the exam.

Zhou is one of the auditees of Peking University and Lu Xun's younger brother. Because Lu Xun was a member of the editorial department of New Youth of the Ministry of Education at that time, Zhou chose to take refuge in Lu Xun. So Lu Xun introduced him to Peking University, worked as an auditor, and then worked in Shanghai Commercial Press.