回複：why? since I140 and 485 has be

http://uscis.gov/graphics/shared/lawenfor/bmgmt/inspect/naftahan.pdf

Page 123,
"8 CFR Sec. 214.6 Canadian and Mexican citizens seeking temporary entry to engage in business activities at a professional level."
"Temporary entry, as defined in the NAFTA, means entry without the intent to establish permanent residence. The alien must satisfy the inspecting immigration officer that the proposed stay is temporary. A temporary period has a reasonable, finite end that does not equate to permanent residence. In order to establish that the alien's entry will be temporary, the alien must demonstrate to the satisfaction of the inspecting immigration officer that his or her work assignment in the United States will end at a predictable time and that he or she will depart upon completion of the assignment. (Paragraph (b) revised 1/9/98; 63 FR 1331)"

Since he filed I140 and I485 before, he may need to convince the CBP officer at POE that his entry is temporary and he will not file for immigration again.