The earth counts time in billions of years. 地球以亿为单位计算时间

141. 4,000 species of mollusks...
     4000种软体动物
142. And 400 species of coral.
     以及400种珊瑚的家园
143. The equilibrium of every ocean depends on these corals.
     每个大洋的生态平衡都取决于这些珊瑚
144. The earth counts time in billions of years.
     地球以亿为单位计算时间
145. It took more than four billion years for it to make trees.
     它花了40亿年造出树木
146. In the chain of species,
     在物种链中
147. Trees are a pinnacle,
     树木位于顶端

来自《家园 第一部分 Home Part1》第 144 行