- And when stalactite meets stalagmite
钟乳石与石笋相遇后
- a column is born.
便形成了石柱
- 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
- can take many thousands of years to develop.
经历了数千年的形成过程
- 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
- 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
- Since the last Ice Age they've become cut off from the outside world.
自从上一个冰川期以来 它们便已和外界隔绝
来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 159 行