Anewstudylinksheavyairpollutionfromcoalburningtoshorter...
問題詳情：AnewstudylinksheavyairpollutionfromcoalburningtoshorterlivesinnorthernChina.Researchersestimatethatthehalf-billionpeoplealivethereinthe1990swillliveanaverageof5yearslessthantheirsoutherncounte...