The quality of air reflects the degree of air pollution, which is mainly judged according to the concentration of pollutants in the air. In China, different cities focus on different developments, different industrial levels, different economic levels, and different cultural environments, resulting in differences in air quality. Specifically, in 2019, China’s air quality ranking.
The Ministry of Ecology and Environment released the “2019 China Eco-Environmental Status Bulletin”, announcing 2019 China’s cities with good ambient air quality and cities with relatively poor air quality. There are 20 cities in each of the two lists. The former includes Lhasa, Haikou and Zhoushan, while the latter includes Anyang, Xingtai and Shijiazhuang. What is the national air quality in 2019?