You can't. Whether you can choose the education mode of one plus three depends on the specific situation of the school. One plus three education mode refers to the combination of senior one and senior two, and then senior three studies professional courses. This educational model is generally suitable for students with good middle school foundation and strong learning ability. The nine-year compulsory school in Beijing refers to a complete middle school that combines primary school and junior high school, with a schooling of nine years. According to the regulations of Beijing Municipal Education Commission, students in nine-year compulsory schools can take the senior high school entrance examination, and after being admitted to high schools, they can also apply for ordinary high schools, secondary vocational schools, technical schools and other schools.