Special thanks to teacher pjiang.
Don't be too worried if you get RFE. Just submit doc. according to the request, it is not as bad as you would think. I was very worried about my RFE & tons of assumputions were in my mind. Actually, it was just as simple as providing the fact.
Another thing is that don't rely on the lawyer too much. Some lawyers would exedurate the situation & create unnecessary panic.