Our appointment is at 2:00 pm we arrived at the USCIS 30 minutes prior to the interview. An hour later my name was called we went to a room together with our lawyer (my brother in law). Handed the bonafides (joint bank account, memberships, insurance and new pictures) We had the oath taking and answered YES or No (Reference Form I-485 pages 3 to 4) and he just started talking to my husband and lawyer randomly and checked our photo album. And then he just handed me the paper that says "Congratulations your application has been approved" 2 years conditional green-card. The interview took less than 10 minutes. It was an awesome experience!!!!!!!!
TIP: Just be yourself and do not be afraid to ask the officer if you don't understand anything. Do not elaborate answer if not asked to do so. And listen carefully to the questions.