請問8老師和各位同學，我申請的EB1A， 140早已批，準備最近去廣州辦移民簽證。簽證時需提交一份offer letter， 提示我去美國後有工作，不會成為美國的負擔。一個朋友給我出了一份 offer letter。
我的問題是：
1. 我拿到簽證後先去別的城市取我寄存的東西所以機票目的地不是offer所在地，入境時會有問題嗎？
-Should be fine. Just explain it to the CBP officer at the port of entry if they question you about it.
2. 我一定要為簽證時提交的offer工作嗎？
-Normally the VO in the US Copnsulate will require it, so you don't have a choice.
還是可以入境後找到其它工作，可以的話是否一定要幹與research 相關的工作？
-The job offer must be in the same field as you claimed for EB-1A.
我能拿到綠卡後能直接去讀書嗎？非得工作的話，能Parttime 工作和學習嗎？
-You had better work for the employer who offered you the position for some time, e.g. for about 6 months, then you can change job or go to school, in case USCIS might think you have fraud in green card application.
3. 我想到美國後，家人留在美國，而我盡快回國工作一段時間。一般入境後多久能拿到綠卡？
-You will receive the pasltic card in about one month.
拿到後能立即回國嗎？
-Technically, yes, but you had better work for the employer for a while. See above.
能回國的話可在國內呆多久？
4. 綠卡到手前可以回國等綠卡嗎？
-Technically, yes. Your immigrant visa will be endorsed at the port of entry. The endorsed immigtrant visa is eqal to green card which is valid for one year, and you can use it to travel.
我到美國後辦好各種綠卡的paperwork和打手印後回國，這邊家人幫我寄綠卡回國，我再用綠卡入境美國可行嗎？
謝謝大家了！
