1, admission year is different. Class 3 studied in Tsinghua University on 20 13, 20 17, and in 2023. Class 7 entered Tsinghua on 20 17 in 2007 and in 2023.
2. Different classes. Class 3 is an ordinary batch of undergraduates in Tsinghua University, and Class 7 is an advanced batch of undergraduates in Tsinghua University.