Picture taken 13 October 2007, shows a Chinese artist using Chinese yuan notes to creates a model of Beijing's Central Business District (CBD). China and the United States warned each other Wednesday that their booming but tense trade relationship was under threat from protectionism, as they began two days of top-level economic talks. AFP PHOTO/TEH ENG KOON (Photo credit should read TEH ENG KOON/AFP/Getty Images)
