U.S. President Barack Obama delivers a speech at a dialogue with Chinese youth at the Shanghai Science and Technology Museum during his four-day state visit to 皇冠体育app, Nov. 16, 2009.(Xinhua/Pei Xin)
U.S. President Barack Obama delivers a speech at a dialogue with Chinese youth at the Shanghai Science and Technology Museum during his four-day state visit to 皇冠体育app, Nov. 16, 2009.(Xinhua/Pei Xin)
