Yeah, I'm pretty sure they tell you to stand.
China and Canada are both the standing Circlevision films. I saw and enjoyed both this year. China is in the main/central round building as I recall and is easy to find. Canada is way back in the pavilion; you have to watch the signs, and there are a lot of stairs (up and down, as I recall) to get there.
I love the France movie (regular theatre/seats) and saw it twice this year. I love the classical music. It's at the back of the pavilion but easy to find. There should be a CM there to tell you how long to the next show, unless they are in the lobby getting ready to admit the next audience.