听力文本

Wild Bactrian camels, one of the rarest mammals on the planet, and perhaps the hardiest.
野双峰驼，一种地球上最稀有的哺乳动物，可能也是最坚韧的动物。
Their biggest problem is the lack of water,
它们最大的困难莫过于缺水
particularly now in winter when the little there is is locked up as ice.
尤其是现在--冬天，那里仅有的一点水也结成了冰。
Surprisingly, snow here never melts. The air is just too cold and too dry for it to do so.
奇怪的是，这里的雪永远都不会融化。又冷又干的空气使它们无法解冻。
The sun's rays turn it straight into vapour. It evaporates.
阳光把它们直接变成了水蒸气。它们升华了。
But it is the only source of water, so Bactrian camels eat it.
可是这是唯一的水源，所以双峰驼只能吃雪。

Elsewhere in the world, a camel at a waterhole can drink as much as 200 litres during a single visit.
在世界上其它地方，一只骆驼找到水坑后，能一次喝下200升水。
Here, the strategy is to take little and often, and with good reason for filling the stomach with snow could be fatal.
但在这里的饮水策略却是少而频繁，这当然有充分的理由，因为肚子里装满雪将是致命的。
The camels must limit themselves to the equivalent of just 10 litres a day.
骆驼必须限定自己每天只能吃10升左右的雪。

视频及简介

陆地的表面大约30%部分是沙漠，这些地区虽然严重缺水，生态系统却异常的多样。揭开沙漠地区的生存秘密，体验这种动态系统中短暂的自然本性。