The combined photo taken on June 18, 2013 shows the displayed pictures during a photo exhibition showing the works of Sidney D. Gamble in Beijing, capital of China. The exhibition displayed more than 100 photos taken by Gamble depicting the life of Beijing from 1908 to 1931. (Xinhua/Li Xin)

　　A man watches pictures during a photo exhibition displaying the works of Sidney D. Gamble in Beijing, capital of China, June 18, 2013. The exhibition displayed more than 100 photos taken by Gamble depicting the life of Beijing from 1908 to 1931. (Xinhua/Wang Jingsheng)

　　A visitor watches pictures during a photo exhibition displaying the works of Sidney D. Gamble in Beijing, capital of China, June 18, 2013. The exhibition displayed more than 100 photos taken by Gamble depicting the life of Beijing from 1908 to 1931. (Xinhua/Wang Jingsheng)