Guangzhou: Guangzhou, whose 2011 GDP of $190 billion eclipses Algeria's, anchors Guangdong province -- which, if it were its own country, would rank among the world's 25 largest economies. Chinese officials hope to link Guangzhou, already home to nearly 12 million people, and its sister cities in the Pearl River Delta to create a "megacity" of 42 million inhabitants spread across 16,000 square miles. Here, stranded passengers at Guangzhou Railway Station wait below a viaduct in January 2008. Fourteen provincial-level regions were struck by the historic cold weather, which paralyzed air, rail, and highway traffic and left over 150,000 rail passengers trapped in Guangzhou.
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