What schools do the "Warsaw Pact", "NATO" and "Three Kingdoms Killing" which are popular in education recently refer to?

NATO: Peking University, Beihang University, Beijing Normal University, Hong Kong University, Fudan University, Nankai University, Xiamen University, Wuhan University, Sichuan University, Shandong University, Lanzhou University, Sun Yat-sen University and Huazhong University of Science and Technology.

Kazuki Watanabe musician: Tsinghua University, China Renmin University, Shanghai Jiaotong University, University of Science and Technology of China, Xi Jiaotong University, Zhejiang University, Nanjing University.

Excellent: Beijing Institute of Technology, Chongqing University, Dalian University of Technology, Southeast University, Harbin Institute of Technology, South China University of Technology, Tianjin University, Tongji University, Northwestern Polytechnical University.

There is actually another Kyoto: University of Science and Technology Beijing, Beijing Jiaotong University, Beijing University of Posts and Telecommunications, Beijing Forestry University and beijing university of chemical technology.