When I heard about that big earthquake happened in China a few months ago, the first thing I thought was: There’s a city of 10 million people that I’d never even heard of? It was an astonishing feeling, and this documentary about modern China and some of the things we Westerners never see about it made me feel the same way.The feature debut from Chinese-Canadian filmmaker Yung Chang, this is a look at life along the Yangtze River as it was being dramatically transformed by the creation of the massive Three Gorges Dam, which Chang explores mostly through Yu Shui, a 16-year-old child of subsistence farmers about to be flooded out off their poor land by the rising river. She goes to work on a cruise ship taking a bizarre tour of the slow-motion disaster for rich Westerners, where her employers teach her English and manners — all the better to interact with the tourists — and it’s all so shockingly Victorian that you almost can’t believe it. As Yu Shui flounders amidst the cultural upheaval of modern China, her coworker Chen Bo Yu revels in it, but he comes from a different China, middle-class and urban and coddled: he’s one of the favored “little emperors,” young men spoiled by their parents and society alike since the nation implemented its one-child-only policy. But the contrasts between these two youngsters is nothing to our culture shock at discovering the unseen world of this rising nation.