Congradulation! I guss you must be given a number before RFE.回复：

I received I-485 RFE on 12/03/2007 and responded RFE 02/12/2008. My case has updated four times: 02/12, 02/13, 03/10,and 03/11(today), but the content has not been changed. How many times did your case updated before approval? Which center? Thanks.