1, all-round development. Junior high school summer school security office will not cause students to be biased, promote students' all-round development, and only apply for mathematics, which will lead to bias.
2. Long study time. The study time of security department in junior high school and summer vacation class is relatively long, so students will play mobile phones for a long time, only report math, and the study time is very short. In the rest of the time, students will be obsessed with mobile games.