Residents in Liaocheng City, east China's Shandong Province, ride motorcycles through smog on the morning of December 5. The National Meteorological Center issued a blue alert early Monday morning, the lowest level in the country's four-scale fog alert system. It said that heavy fog will continue to cover the country's northern and eastern regions during the morning, creating safety risks on roads and docks, as well as at airports (XINHUA) |