Yet these glaciers play an essential role in the water cycle. 然而这些冰在水循环中是必不可少的
They are an essential link in the chain of species. 他们是物种链中不可缺少的一环
Deforestation destroys the essential to produce the superfluous. 森林砍伐是舍本逐末
That is so essential to life on earth. 对地球上生命至关重要的平衡
Open communication is essential to a healthy relationship. 健康的情侣关系应该是坦诚相对的
..and essential for life on Earth. 淡水对地球上的生命至关重要
Without these essential gardeners - 没有这些不可或缺的园丁
The essential nutrients carried in these plumes 烟雾中携带的基本营养物质
And on some islands that is essential. 在某些岛上 这是必备的生存技能