刚和过去的一位朋友联系过，他的情况和我的一样。然而，在他当初递交I-485时，他的律师坚持：“Date of Last Arrival“ 应该是从加拿大回美国的时间。结果悲剧了！ 然后另请律师，又花了近 $8000 和三年多的时间才拿到绿卡。不过，他自己和他的律师 并不十分确定，“Date of Last Arrival“ 应该是哪个时间，因为后来他有提交了整整2个箱子的材料（寄到移民局），证明自己是合法入境，不知道究竟是哪个材料其了作用。
-Just do what I suggested above. If USCIS send you RFE about your travel to Canada, then you can explian it later. Now you do not need to mean it in your I-485 filing. Technically, only if you surrender your I-94 when you leave US and then, get a new I-94 when you reenter US, then can you be considered that you have been out of US and returned.
The definition of an I-94:
The form I-94 is the Arrival / Departure Record, issued by a CBP Officer to foreign visitors entering the United States.
The I-94 must be turned in to a CBP Officer at a land border or airline representative when the visitor exits the U.S.
