听力文本

The droppings also support other types of cockroaches,
粪便也能养活其它种类的蟑螂
which spend part of their day resting on cave walls.
它们一天大部分时间都呆在洞壁上
These in turn become food for giant cave centipedes, some more than 20 centimetres long.
这些蟑螂也接连成为了洞穴大蚰蜒的美餐，有的蚰蜒能长到20厘米长。
Bizarrely, there are crabs here, too. Sifting through the droppings for nutrients.
奇怪的是，这里甚至还有螃蟹，它们从粪便中过滤营养物质。
All these animals spend their entire lives within the cave.
所有这些动物都在洞穴内度过一生
They're totally dependent on the digested remains of food that's brought in from outside.
它们完全依赖的食物消化残渣都是来自于外界

Each evening, in just two hours, three million bats leave the safety of the cave
每天傍晚，只是前后2小时内，300万只蝙蝠一起离开安全的洞穴。
to hunt for insects in the forest outside. But not all will return.
在森林外围捕食昆虫。但并非所有的蝙蝠都能返回。
As they leave the cave, the stream of bats form a doughnut-shaped ring.
蝙蝠离开山洞后，即在空中组成一个面包圈一样的队列。
The wheeling bats seem to confuse a rufous-bellied eagle,
旋绕的蝙蝠群似乎已将棕腹隼雕弄得晕头转向
but they must still survive the attacks of other, more specialised birds of prey.
但它们仍须躲过其它更专业的猛禽的攻击。

词汇解析

1.in turn 依次 轮流
We can consider each aspect of a development environment in turn.
我们可以依次考虑开发环境的每一个方面。

2.be dependent on 依赖；取决于
Never be dependent on anybody, for anything. Learn to be independent.
不要依赖任何人或者任何事物。学着独立自主。

视频及简介

洞穴是不受阳光控制的生物栖息地之一，但这并不意味着那里就不存在野生生物。本集节目将深入洞穴内神秘而永恒的黑暗，探索山洞、洞穴和隧洞中未知的地下世界。