回複：謝謝，但是我是在這裏申請的F1，所以passport上沒有stamp.而I94上隻有valid until DS

這種情況，我今年夏天回國會有問題嗎？
-What was your previous status before you changed it to F-1?  If you leave US,  you need to apply for the F-1 visa to come back.
I20是到2015年。