回複：thanks a lot! I asked lawyer's assitant already

my case was with TSC.
Emergency AP is only issued when emergency situation exist. You need to present Dr's note (with English translation and notary certificate). Also you need to check with local INS to see whether they issue AP based on employment-based I-485 pending. My local INS doesn't do that and I wasted a 5-hours driving. So check with them first if you don't live close to your local INS.
Good luck.