請XBT和各位專家幫忙: EB2 I-485 要被麵試

我LP(主申請人)的三周前綠卡已經批了,我的一直沒信,知道今天收到EMAIL,我還以為是批準了呢,打開一看,您猜怎麽著?
Current Status: This case has been sent for a standard interview.
On July 17, 2007, we transferred this case to our LINCOLN, NE location to conduct the interview that is a standard part of processing this I485 APPLICATION TO REGISTER PERMANENT RESIDENCE OR TO ADJUST STATUS. You will be sent a notice when the interview is scheduled, or if the office needs something from you.

我們是EB2, PD 1/2005. 為什麽我會被INTERVIEW?回想過去在美國八年,沒幹過什麽違法的事阿.他們會問些什麽?需要準備什麽?多久能收到麵世通知?麵試後多久USCIS做決定?

還有,我在SAN JOSE(CA),為什麽他們要transfer case to LINCOLN, NE?