BBC.地平线.2020.从七十七亿人口开始  

According to the UN, it is predicted that the human population could reach ten billion people by the year 2050. For broadcaster and naturalist Chris Packham, who has dedicated his life to championing the natural world, the subject of our growing population and the impact it is having on our planet is one of the most vital – and often overlooked – topics of discussion in an era ..真正的朋友，会在你需要时伸出援手，不问原因，不计代价。