Three plus one certificate, let me give you an example: for example, you study in a technical secondary school and now you want to study in a full-time junior college or undergraduate course. In some places, three students started undergraduate courses. 3 stands for Chinese, Mathematics and English. 1 refers to a vocational skill certificate, such as a first-class computer certificate or an accounting certificate. Different majors need different certificates. Some require 3+2 certificates.