Thanks. After I came back from Mexico in Aug. 2007, I didn't go back to China; however in Nov. 2007, I crossed the border to Canada and went back immediately just to change my status back to F1, and I have the I-94 for this entry. If this is the case, do I still need to replace the missing F1 I-94 when I came to the country from Mexico?
-Then, you do not need to get the repalcement and don't need to provide any I-94s before that date when you came back from Canada in Nov. 2007. Your last entry date was Nov. 2007 and the I-94 was the one you got at the port of entry when you re-entered US from Canada and you just put this information in your Form I-485.
