After a decline due to the Covid-19 lockdowns, air pollution levels are bouncing back to their pre-pandemic numbers, according to an analysis of satellite imagery.
원문출처 : https://www.cnn.com/2021/03/16/us/covid-air-pollution-return-trnd/index.html
원문출처 : https://www.cnn.com/2021/03/16/us/covid-air-pollution-return-trnd/index.html