科學家承認“汽車尾氣”是霧霾元兇
從昨天下午開始，濃重的霧霾又開始籠罩京城。不久前中科院出了一個研究結果，稱汽車尾氣及垃圾焚燒僅占PM2.5
Although scientists have not agreed on an exact percentage of vehicle exhausts' contribution to fine particulate matters in big cities, they do agree it is a major source of pollution.
盡管科學家們對于汽車尾氣在大城市PM2.5 汽車尾氣的英文表達是vehicle/automobile exhausts，它和soil dust 目前為了減少汽車尾氣，各大城市都開始實行restrictions on purchasing motor vehicles
