A woman covers her nose and mouth with scarf in Harbin, capital of northeast China's Heilongjiang Province, Oct. 25, 2016. Heavy smog hit the city on Tuesday. (Xinhua/Wang Kai)
A woman covers her nose and mouth with scarf in Harbin, capital of northeast China's Heilongjiang Province, Oct. 25, 2016. Heavy smog hit the city on Tuesday. (Xinhua/Wang Kai)