Africa's Sahara is the largest desert of all. 非洲的撒哈拉沙漠是世界上最大的沙漠
The Gobi, hostile though it is, is their last stronghold. 戈壁尽管环境险恶 却是它们最后的据点
There is one simple and massive cause - 这里有一个简单而又重要的原因
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双峰驼 吸引路过的母骆驼的一种方式
Here the strategy is to take little and often. 但在这里的饮水策略却是少而频繁
But it is the only source of water, 可是这是唯一的水源
The air is just too cold and too dry for it to do so. 又冷又干的空气使它们无法解冻
Their biggest problem is the lack of water, 它们最大的困难莫过于缺水