非常非常感谢您的指导。我会和学校international office联系。在您的回答中，我有几点不明白，请指点：
1.我是否还需要申请J-1 category from J-1 researcher/scholar to J-1 stduent??
-If your old J-1 category was J-1 student, you need to to J-1 transfer. ？？？
-------------I don't understand the answer,could you give me a favor to explain it?
-Are you an J-1 student now or a researcher (what do you do with your current J-1, study or work?) If you study, you are J-1 student and just need to do J-1 transfer form your current school to the new school. If you work, you need to do the change of J-1 category. Anyway, talk to both your current school and your new school international scholar offices and they will help you.
I really appreciate your patience and help!!!
如果可以以J-1身份读书，sponsor的单位应该是谁？
-It is the New school and you need to get another DS 2019 from your new school.
---------------------我仍然只需要waiver一次，即使拿到新的DS2019,我的理解对吗？
-Correct.
