已拿到新I－２０，秋季入學
如果等到年底再回國（入學一學期後）是否可以代簽？
-F-1 visa is valid for one year, so not need to get the new F-1 visa if visiting China in the end of this year. You can use 代簽 within 48 months after the F-1 visa expires.
