Three major US cities being wreathed in smoke from massive wildfires now have the worst air quality of any big cities in the world, according to a monitoring group.
원문출처 : https://www.cnn.com/2020/09/14/weather/wildfire-air-quality-trnd/index.html
원문출처 : https://www.cnn.com/2020/09/14/weather/wildfire-air-quality-trnd/index.html