Scientistshavehelpedpeopleunderstandthedangersfacingthe...
問題詳情：Scientistshavehelpedpeopleunderstandthedangersfacingtheearth.Aspeopleliveontheearth,weshouldbefullyreadytodealwiththedangers.Ifwedonotpaymoreattentiontotheproblemscausedbyairpollution,ourearth...