预习 新知早知道UNIT 3 ENVIRONMENTAL PROTECTION starve release moderate annual volume campaign sensitive nuclear garbage ecology melted releasing worldwide trends policy undergo submitted sensitive restore campaign starvation habitable sustainable worldwide frequently restriction harmonious regulation inspection conservation 北极熊仅存的只是“皮包骨头”意味着这只熊不能像以前那样捕猎海豹“自然”温室效应和“人为”温室效应捕获了一些热量不仅造成严重破坏，而且造成人员伤亡谢谢观看 THANK YOU!
