回複：急，我的I-485申請被退回來了，懇請幫忙。

1. Since all my application forms was signed on 4/13/2006, do I need to re-sign all the forms with current date?

-- do not need re-sign, if you can send ASAP.


2. My employment letter provided by my company was signed on 3/31/2006, do I need to ask for another new employment certification letter with current date?or I can use the existing one to file as soon as possible?

-- that's fine to use old one. If you are employer based I-140, it is better to re-sign.


3. What kind of mail service from USPS should I use, priority mail with signature confirmation, or priority mail with tracking, or Express mail? which one do you use to send I-485 application to NSC?

Fedex