A citizen rides bicycle amid heavy fog in Taizhou, east China's Zhejiang Province, Feb. 24, 2013. Some regions in Zhejiang Province were hit by heavy fog on Feb. 24 morning and local meteorological bureau has issued yellow alert for the fog. (Xinhua/Huang Zongzhi)

A citizen does morning exercises amid heavy fog in Taizhou, east China's Zhejiang Province, Feb. 24, 2013. Some regions in Zhejiang Province were hit by heavy fog on Feb. 24 morning and local meteorological bureau has issued yellow alert for the fog. (Xinhua/Huang Zongzhi)