2. Expansion rate. Cities are growing at an alarming pace. The amount of construction going on everywhere is amazing. With a good view of the town, I could see half a dozen cranes. In America, a skyscraper may be built and it would take several years. In China, you literally see half a dozen cranes right next to each other building 10 skyscrapers at the same time to be completed in a few months. Leaving and coming back in a couple of years means entire cities have sprung up that weren't there before.