【正文】
e spread of nuclear weapons in his talks with Chinese President Hu Jintao.He announced the United States would expand the number of students to study in China to 100,000 to enhance ties between the two countries.After the speech, Obama answered questions raised by the audience and Internet users, which varied from ShanghaiChicago exchanges and his first impression about China to cultural diversity and the latest development in Afghanistan.Obama arrived in Shanghai late on Sunday to begin his fourday state visit to China.He met Shanghai city officials Monday morning before meeting with young Chinese and left for Beijing in the afternoon.