Night feeders leave the cave each evening. 它们每天晚上出洞觅食
Cave exploration often requires you to push yourself through narrow gaps in the rock. 洞穴探险需要不时挤过 一些狭窄的岩石缝隙
a technique that has been used here, in Mexico, to chart the largest underwater cave in the world - 在墨西哥的这个地方 这种科技被用来 测绘世界上最大的地下水洞
But in the darkness of the cave tunnels 但是在黑暗的洞穴通道内
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
then the calcite is deposited on the floor of the cave 方解石就会在洞穴地面上沉积
and when it meets the air in the cave 当它与洞内空气接触时
The pure white nests of cave swiftlets 洞金丝燕的纯白燕窝
and using ladders made from forest vines the gatherers climb into the highest reaches of the cave 采集者利用树藤编成的梯子爬到洞穴的最高处
For 500 years people have been harvesting the nests of cave swiftlets. 500年来 人们一直采集洞金丝燕的燕窝