非常感谢8老师耐心的解答！还有一事想请教：
一旦移民局批准我的DS-260并且发出引见信邀请我去广州使馆面谈，如果我去了，要么拿到移民签证回美国，要么被驳回连F1都被取消了就再也回不来了，我这样说准确吗？
-Right, but as long as your mother gets the immigrant grant visa, you should have no problem to get it. You don't need to leave US until you get the appointment notice for the visa interview. By the way, if you get the immigrant visa in China, you need to come back to US together with your mother or after your mother enters US. You can not enter US before your mother.
那么我的F1学生签证具体是在哪一步哪一个时间点失效的呢？
-When you leave US, then you will have a problem to come back if you want to use F-1 visa.
如果待在美国等待父母移民入关后申请I-485，请问依然可以用之前的F4亲属移民来申请吗，
-Yes. As long as you are not age-out, you just need to file I-485 to get the green card within US after your mother enters US (you need to provide the copy of your mother's endorsed immigrant visa stamp or her green card, and the copy of the I-130 approval notice).
还是F2亲属移民？
请问之前有先例成功吗？
-Yes. No problem at all, and it just delay your green card a little (you have to wait for your mother to become the green card holder, then you can be qualifed for I-485 filing) if you want to file I-485 to get the green card.
因为查到的先例好像都是回国面谈，也不知道最终结果，只是觉得风险好大，有可能无法继续读书。
谢谢8老师的耐心解答！
