英语听力：探索发现 科学新发现：我们的大气层-1

 In the empty blackness of space surrounded by hostile planets and freezing vacuum, planet Earth is an oasis¹ of life. And all because of our protective cocoon² of gas. This blanket of air shapes everything we see on Earth. It protects, insulates and sustains us. It carries the water around the globe, and shields us from cosmic impacts and killer³ radiation. It’s time to uncover the invisible wonder. That is our atmosphere.

 

Down here on the Earth, we rarely give much thought to our atmosphere, because we can’t see, smell, taste or hear it, we take it for granted. But our air is all that stands between us and the vacuum of space. We’ve got this canopy⁴ that provides us a lot more than just an atmosphere to breathe in. It definitely shields us. The atmosphere is divided into five distinctive⁵ layers, the troposphere, stratosphere, mesosphere, thermosphere and exosphere. Each layer is less dense⁶ than the one below, stretching miles above our heads. How far out it goes is depending on which scientist you talk to. Some say it ends at three hundred miles. Some say it extends out to Mars. We live in the layer closest to the ground. Here in the troposphere, the air is thickest and the pressure greatest. Our bodies are perfectly⁷ matched to these conditions.

1 oasis   

n.（沙漠中的）绿洲，宜人的地方

参考例句：

• They stopped for the night at an oasis.他们在沙漠中的绿洲停下来过夜。
• The town was an oasis of prosperity in a desert of poverty.该镇是贫穷荒漠中的一块繁荣的“绿洲”。

2 cocoon   

n.茧

参考例句：

• A cocoon is a kind of silk covering made by an insect.蚕茧是由昆虫制造的一种由丝组成的外包层。
• The beautiful butterfly emerged from the cocoon.美丽的蝴蝶自茧中出现。

3 killer   

n.杀人者，杀人犯，杀手，屠杀者

参考例句：

• Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。
• The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。

4 canopy   

n.天篷，遮篷

参考例句：

• The trees formed a leafy canopy above their heads.树木在他们头顶上空形成了一个枝叶茂盛的遮篷。
• They lay down under a canopy of stars.他们躺在繁星点点的天幕下。

5 distinctive   

adj.特别的，有特色的，与众不同的

参考例句：

• She has a very distinctive way of walking.她走路的样子与别人很不相同。
• This bird has several distinctive features.这个鸟具有几种突出的特征。

6 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

7 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。