听力文摘：骆驼（在线收听）

A camel can travel hundreds of miles, over several days, without stopping to drink.

骆驼可以行走数百英里，并在几天之内也不用喝水。

On today's Moment of Science, we'll learn how camels survive the dry desert.

在今天的科学一刻中，我们将会学习骆驼是怎样在干燥的沙漠中生存的。

Let's start with the hump.

我们先从驼峰说起，

Contrary to what you might have heard, camels do not store extrawater here.

和你所听说的不一样的是，骆驼并没有储存多余的水在这里。

The hump stores fat, providing energy for their long, desert trek.

驼峰积聚着脂肪，为它们长距离的沙漠旅行提供能量。

This fat, however,can help keep a camel from getting thirsty.

然而就是这些脂肪，可以帮助骆驼止渴。

As the fat is burned, water is produced as one of thebyproducts.

水就是这些脂肪燃烧所产生的副产物之一。

This extra water enters the camel's bloodstream to add to its water supply.

这些额外的水进入骆驼的血液，增加其水分的供应。

Camels conserve water by not sweating as much as we do.

骆驼不像我们那样出汗，这样也可以储存水分。

A camel's metabolism lowers at night,making its body temperature much lower than a human's.

骆驼的新陈代谢到晚上就会降低，让它的体温低于人类。

Because we sweat to cool ourselves off,starting with a lower body temperature means less need to sweat.

出汗可以冷却我们自己，因此如果体温较低的话，对汗水的需求也会比较少。

Camels are also covered withheavy fur which keeps the daytime heat out.

骆驼同样覆盖着厚重的皮毛，这些皮毛可以防止白天的热量进入体内。

Because it's so good at keeping its cool, a camel cantravel a long way without sweating very much.

正因为骆驼如此擅长保持其身体的冷却，所以它可以走很长时间，却不会流很多汗。

Camels are also good at maintaining their blood volume.

骆驼同样也很擅长保持它们的血容量。

Once we humans lose about twelvepercent of our body's water, our blood becomes too thick to work properly.

我们人类一旦流失了身体百分之十二的水分，血液就会变得太浓稠以至于不能正常工作。

A camel's blood,however, stays more or less consistent, allowing the camel to lose up to twenty-five percent of itsweight by dehydration.

可是骆驼的血液，总是可以坚持到让其脱水到其重量的百分之二十五。

Another thing that helps a camel conserve water is its nasal passages.

另一个有助于骆驼储存水的东西就是鼻腔。

When we exhale, we loosea lot of water vapor, as any fogged up car window will prove.

当我们呼气的时候，我们会流失许多水蒸汽，被雾气模糊的车窗可以证明这一点。

Camels have extra dry nasalpassages which actually recondense the water out of each breath, allowing much less to escape.

骆驼有额外的干燥鼻腔，可以凝聚每次呼吸的水分，让水分的蒸发的变少。

As you can see, there is no single explanation for a camel's desert survival abilities.

就如你所见，没有关于骆驼沙漠生存能力的单一解释。

Instead, a cameldraws on a whole range of adaptations.

相反地，骆驼有一系列的适应能力。