AOS Interview for parents at local USCIS office

[chpatel]

Hi,
I am a US citizen and have filed I-130 & I-485 (concurrent filing) for my parents. They had their first fingerprinting appointment on Dec 30th, 2010. This week we got notice of action asking them to appear for interview. My questions are

1. As a petitioner can I accompany them
2. Can I act as their interpreter or do I need someone else (not related to us family wise)
3. What type of questions are asked.
4. Is it normal to get an interview call (I have had friends whose parents GC were approved without interviews)

Your advice and comments are greatly appreciated. Also, if you don't mind can you share your experience if you have similar situation.

[immihelp]

1. Yes.
2. Yes. You can do it.
3. Varies.
4. Depends.