In April, the concentration of PM2.5 in Beijing was 31 u03bc g / m3, the lowest in history

category:Global
 In April, the concentration of PM2.5 in Beijing was 31 u03bc g / m3, the lowest in history


(function() {(window. Slotbydup = window. Slotbydup| []). Push ({ID: u5811557, container: ssp_, async: true});}) (); source of this article: responsible editor of Beijing News: Zhang Chao