不用客气

The IRS has this Substantial Presence Test to determine US tax residency status. The test counts how many days you have been present in the United States. If you have been present in the United States for at least 183 days during a three-year period that includes the current year, you are no longer a nonresident alien for tax purposes. However, students present in the US under F, J, M and Q visa are exempt individuals (students are exempt for 5 calendar years, 2 years for non-students).

Even if you dont have file tax return, it's required that you must file Form 8843.

you welcome!

好像来美的机票不能deduct的吧。具体还有哪些可以抵税的可以看看税表的instruction，偶没怎么填过J的tax return