About 4,000 years ago,Bactrian camels were domesticated.

大约4000多年前们驯化了。

But it is the only source of water, so Bactrian camels eat it.

可是这是唯一的水源，所只能吃雪。

So Ganbold and his twin-humped Bactrian camels must chase the snow towards the mountains where it lingers.

所勒德和他的必须循着雪花，向着它们所属的山脉赶去。

This extraordinary performance is a male Bactrian camel's way of attracting the attention of a passing female.

这种奇怪的表演是公吸引路过的母骆的一种方式。

China is one of the main habitats for Bactrian camels in the world, but the ancestral home of camels is in North America, far away.

中国是世界上的主要栖息地之一但骆的祖籍却在遥远的北美洲。