回复：绿卡还未拿到（LC已批）。护照已过期。手上无护照。

Sooner or later you will need show your valid passport, for GC and for your future citizenship. What you need to do is to ask for a stamped letter from your previous orgonization to prove you have no financial connections with them. You don't need their agreement on the transition to private affair passport. My feeling is the embassy is now having more flexibility than before on this issue.