Local residents do morning exercises in the fog in Wujiaqu City of Xinjiang Uygur autonomous region Nov 26, 2013. About 7,600 passengers were stranded as 128 flights were affected by the heavy fog over Urumqi International Airport on Tuesday. Visibility fell to less than 100 meters on airport runways and 91 flights were delayed, while another 37 were canceled. [Photo/Xinhua]