Question about Labor Substitut longstanding2005-07-21 14:52:37

I have a pending Labor Certificate (LC). Last week, I filed my I-140 with a substitute LC from someone else. My questions are

1. Can I file 2nd I-140 after my own LC is approved?
2. Can I keep my old Priority Date (based on my own LC) when filing 2nd I-140?
3. Will substite affect my old priority date??

Thank you very much!