Many scientists say it's abundantly clear that Earth is entering its sixth mass-extinction event, meaning three-quarters of all species could disappear in the coming centuries.
원문출처 : http://www.cnn.com/2017/07/11/world/sutter-mass-extinction-ceballos-study/index.html
원문출처 : http://www.cnn.com/2017/07/11/world/sutter-mass-extinction-ceballos-study/index.html