Photo taken on Dec. 17, 2011 shows a pair of twin giraffes "Ping Ping" and "An An" in Shijiazhuang, capital of north China's Hebei Province. Shijiazhuang Zoo invited more than 10 pairs of twin children to celebrate the one-year-old birthday for China's first twin giraffes here on Saturday.(Xinhua/Ding Lixin)
