the missing ingredient for animal life to exist... 这是动物生命存在不可或缺的元素
Survivors that would form the basis of all species that exist today. 这些幸存者将成为 今天存在的所有物种的基础
Programs exist that guarantee sustainable forest management. 这一规划确保了森林资源的可持续发展
This can't exist. You get that, right? 这不现实 你明白 是吗
We now know that such relationships exist in forests all over the world. 这样的依存关系在全世界的森林中普遍存在
Grasslands occur where rain is too sporadic for forests to exist. 降雨量不足以养育森林时就会出现草原
without fungi, rainforests could not exist. 没有菌类就没有雨林
Grasslands exist wherever there is a little rain, but not enough to sustain a forest. 草地无所不在 一点雨水虽然不足以维系一片森林 却可使一片草地存活下来