CHINA’S national observatory renewed a yellow alert Saturday for thick fog. Heavy fog is expected to affect parts of Tianjin, Hebei, Henan, Shandong, Jiangsu, Anhui and Hubei, according to the National Meteorological Center. Visibility in some affected areas will be reduced to less than 500 meters, and in some instances, even below 50 meters, the center said. Motorists are advised to control their speed, while precautionary measures should be taken at airports, expressways and ferry terminals to ensure traffic safety, the center said.(Xinhua) | 