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

大约4000多年前人们驯化了双驼。

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

可这唯一的水源，所以双驼只能吃雪。

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

所以冈包勒德和他的双驼必须循着雪花，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.

这种奇怪的表双驼路过的母骆驼的一种方式。

Milked mammals include the cow, sheep, goat, horse, reindeer, water buffalo, yak, and Arabian and Bactrian camels.

挤奶哺乳动物包括牛、绵羊、山羊、马、驯鹿、水牛、牦牛、阿拉伯骆驼和双驼。

The domestic animals that were ridden were the horse, donkey, yak, reindeer, and Arabian and Bactrian camels.

骑乘的家畜有马、驴、牦牛、驯鹿、阿拉伯骆驼和双驼。

Arabian and Bactrian camels played a similar military role within their geographic range.

阿拉伯骆驼和双驼在其地理范围内发挥着类似的军事作用。

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.

中国世界上双驼的主要栖息地之一但骆驼的祖籍却在遥远的北美洲。

Although Alexander's Bactrian wife, Roxana, was pregnant at the time of  his death, there was no viable heir, and Alexander's vast empire fell to infighting  among his generals.

尽管亚历山大的双人妻子罗克珊娜在他去世时已怀孕，但没有合适的继承人，亚历山大庞大的帝国也陷入了将军们的内斗。

The three domestic camel species (Arabian camel, Bactrian camel, and llama) played a similar role in areas of North Africa and Arabia, Central Asia, and the Andes, respectively.

三种家养骆驼品种（阿拉伯骆驼、双驼和美洲驼）分别在北非和阿拉伯、中亚和安第斯山脉地区发挥着类似的作用。

The Macedonian troops who stayed in the city intermarried, and they became the Greco-Bactrian Kingdom, which flourished in Central Asia after Alexander's death.

留在城内的马其顿军队与当地人通婚，成为希腊-巴克特里亚王国，亚历山大死后，该王国在中亚蓬勃发展。