回複：這可能主要看個人的情況，如果你背景複雜，那就時間長，

thanks very much for your reply.

my background is not complicited, after master, i worked for 4 years in a company in China, and then went to Ph.D study in China, after Ph.D, I came to USA directly as a postdoctor. My J1 waiver was processed very easily....