So, I just got the info back after DCFing in Beijing, and it's now time to start prepping for the interview in Guangzhou. I have lots of questions, but for now I'll just ask one...does it matter what language the interview is conducted in? I've read the VOs can usually speak Mandarin and English, but I'm not sure which one to go with...basically, here's our situation. My wife: fluent in Mandarin, OK at basic English. Me: fluent in English, also fluent in Mandarin. We speak both languages to each other, but Mandarin is our "base" language and it's what we usually speak. So, obviously my wife would be more comfortable doing the GUZ interview in Mandarin. However, I'm wonder if they're more likely to reject applicants who can't do the interview in English? Or if she does the interview in Mandarin, would she need to provide some proof that I can speak Mandarin? What sort of documentation should we use for that, email logs perhaps? Perhaps in connection with this, I'm also wondering about providing video evidence, which I've seen mentioned in a few threads...how is this done, logistically? Would it be possible, for example, to bring a video file on a flash drive? Or a DVD? Presumably, a video would be a great way to prove we communicate fluently in Mandarin, but aside from that, what else could a video be used as documentation for?