8 Were you present in the United States as a teacher, trainee , or student for any part of 2 of the 6 prior calendar years (2005 through 2010)? . . . . . . . . . . . . . . . . . . . . . . . . Yes No If you checked the “Yes” box on line 8, you cannot exclude days of presence as a teacher or trainee unless you meet the Exception explained on page 3. 这个第8项,我只能选yes,但是you cannot exclude days of presence as a teacher or trainee是指什么呢?是说J1只能做3年? J1的三年免税是指36个月?还是3个自然年?