If you are admitted to Shanghai Jiaotong University, don't expect to have any special bbs. The drinking water source of Shanghai Jiaotong University is a website for students who have been admitted to graduate schools. You can go to Siyuan online to search for your exam subjects and real questions. There is also the Shanghai Jiaotong University Postgraduate Entrance Examination Forum, so you can pay more attention to it.
The most important thing is that you should find your senior online for detailed consultation, which is very important. You can search on campus, specific to the institutions you want to apply for. They are all willing to help. Good luck!