BEIJING, Feb. 22 (Xinhua) -- China's National Meteorological Center renewed a blue alert for a cold wave on Sunday as the country braces for cold fronts. On Feb. 22 and 23, temperatures are expected to fall by 6 to 10 degrees Celsius across regions including north China's Inner Mongolia Autonomous Region, the northeast China provinces of Heilongjiang, Jilin and Liaoning, as well as Jiangsu Province in east China