A statue is seen in dense fog on a street in Hefei, East China's Anhui province, Jan 14, 2013. [Photo/Xinhua]

A teacher leads a class of pupils doing their exercises between classes in a classroom instead of outdoors, at a primary school in Jinan city, Capital of East China's Shandong province on Jan 14, to prevent students from exposure to the threat of dense pollutants floating in the air due to the heavy fog and haze. The bad weather has been lingering over a large part of China for several days and is expected to continue until Jan 16. [Photo by Zheng Tao /Asianewsphoto]