Teachers of Zhengzhou University can't find the information of previous students. Zhengzhou University will strictly abide by relevant privacy policies and laws and regulations in the management and protection of student information. Access to students' personal information is limited and will only be granted under certain circumstances, such as educational administration, academic research or administrative affairs related to students. Even in these cases, legal and compliant procedures and authorization are needed. Therefore, teachers of Zhengzhou University cannot directly contact the personal information of previous students.