Structures like these in North America's Carlsbad Cavern 北美洲卡尔斯巴德溶洞中的这些构造

155. the slow deposition of dissolved limestone.
     都是由水溶碳酸钙缓慢沉淀而来
156. And when stalactite meets stalagmite
     钟乳石与石笋相遇后
157. a column is born.
     便形成了石柱
158. Structures like these in North America's Carlsbad Cavern
     北美洲卡尔斯巴德溶洞中的这些构造
159. can take many thousands of years to develop.
     经历了数千年的形成过程
160. But sometimes the formations in a cave stop growing altogether.
     但有时洞穴内的这些活动会完全停止
161. These flooded caves in Mexico have remained virtually unchanged for thousands of years.
     墨西哥的这些水洞 几千年来几乎保持不变

来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 158 行