预习 新知早知道UNIT 1 Nature in the balance harm length variety survive thus disappear agriculture impact damage climate further protest absolutely Nowhere former profit various recycle agriculture defenceabsolutely tracker extinction application entirely organization regional economic poisonous living 相当于中国面积的一半以上从山区流到海洋支撑着大量落叶一小群尸体将营养物质还给大地有食用或药用价值的物种宝库谢谢观看 THANK YOU!
