标题: 戰友們幫忙解惑! [打印本页] 作者: hijenny 时间: 2010-6-26 09:45 标题: 戰友們幫忙解惑! Ozone, a special form of oxygen that screens out harmful ultraviolet rays, reaches high concentrations twelve miles above Earth, where it had long appeared immune to human influence; we have now realized, though, that emissions of industrial chlorofluorocarbons deplete the ozone layer.