回复：Confused filing tax return

第一个问题我不知道,你可以问问假博士;
第二个问题,YOU SHOULD FILE 1040NR. 原因: 所有不具备美国公民身份或者绿卡的人,原则上都是外国人.但是如果你在美国呆满183天的话,从税务角度,你可以作为美国公民FILE 1040. 但是以F-1,J-1身份在美国的天数不算在183天内.所以根据你提供的信息,应该不满足183天的要求.英文原文如下：
You will be considered a U.S. resident for tax purposes if you meet the substantial presence test for the calendar year. To meet this test, you must be physically present in the United States on at least:

31 days during the current year, and
183 days during the 3-year period that includes the current year and the 2 years immediately before that, counting:
All the days you were present in the current year, and
1/3 of the days you were present in the first year before the current year, and
1/6 of the days you were present in the second year before the current year.
还有例子：
Example:

You were physically present in the United States on 120 days in each of the years 1999, 2000, and 2001. To determine if you meet the substantial presence test for 2001, count the full 120 days of presence in 2001, 40 days in 2000 (1/3 of 120), and 20 days in 1999 (1/6 of 120). Since the total for the 3-year period is 180 days, you are not considered a resident under the substantial presence test for 2001.