FULL article nextChina has bought up so much copper, pork, and soy—and constructed so many roads, trains, power grids, and bridges—that it’s surpassed the U.S. as South America’s largest trade partner and is now the single biggest trader with Brazil, Chile, and Peru. A Chinese company is leading a group that’s building the metro in the Colombian capital of Bogot. Energy giant State Grid Corp. of China owns the company that supplies electricity to more than 10 million Brazilian homes. In February, Argentina announced that China would finance about $24 billion in infrastructure projects.