Peking University, formerly known as yenching university, was originally a missionary school run by American Si Tuleideng. Once, Mr Si Tuleideng gave a banquet in honor of his new colleague. During the dinner, he asked people about their impressions of the school. Mr. Qian Mu here said: I thought Yanda University was the most China-oriented Christian university in China, but I don't think so. When you enter the school gate, you will see the' M' building, the' S' building, the' Gong Bei' building and so on, but you won't see the slightest China. Suggest changing the name to China.

Mr. Wang accepted this suggestion and immediately held a school meeting, and changed the M building into the Mu building, the S building into a suitable building, and the Gongbei building into an office building. Other buildings were also named China. There is a lake on campus, with pleasant scenery, but it has no name yet. Everyone is vying for the nomination, which is inappropriate. Mr. Qian Mu had a brainwave and said, Let's call it the unnamed lake. Therefore, this unnamed name has been used to this day.