纪录片《地球的力量》第二集 大气07:宇宙的开始

They're thin, wispy clouds that can only be seen in the summer at high latitudes.

它们是稀薄的纤细的云只有在高纬度地区的夏天才能看见

Beginning at nearly 50 miles high,

从50英里(85公里)处开始

there's the fourth layer, the thermosphere.

是第四个气层：热气层

Here, the atmosphere is so thin that beyond 50 miles

这里的大气如此稀薄以至于50英里以外

we approach the beginnings of space.

就可以肯定地认为是宇宙的开始

The space shuttle orbits the Earth in the thermosphere.

正是在这个气层，航天飞机绕着地球飞行

It's also where nitrogen and oxygen

也是在这里，氮气和氧气

interact with the Sun's lethal solar wind,

被太阳风辐射

creating the aurora around the Earth's poles.

创造了环绕地球磁极的极光

There's another way of looking at the atmosphere.

但是这有另一种看待大气层的方式

If you could unwrap the atmosphere from the surface of the Earth

如果你把地球表面的大气层展开

and put it all into a ball, this is what it would look like.

并把它变成一个球，就像我们所看到的这样

Its weight is equal to a layer of water 34 feet deep, covering the Earth.

其重量只相当于覆盖地球34英尺深的水

The layer that we spend our lives in, the troposphere, is just a narrow band.

我们生命所依赖的平流层只是一个窄带

It's a finely balanced mixture of different gases essential for life

它由生命必须的不同气体平衡混合而来

but it also has a physical presence.

但它也有实体存在

重点讲解

1、approach

靠近;接近;走近

He didn't approach the front door at once.

他没有马上走向前门。

When I approached, they grew silent.

当我走近时，他们就不说话了。

与…接洽；找…商量

When Chappel approached me about the job, my first reaction was of disbelief.

当查普尔为这份工作找我商量时，我的第一反应是不相信。

He approached me to create and design the restaurant.

他请我建造并设计该饭店。

探讨；处理；对待

The Bank has approached the issue in a practical way.

银行已经实际解决了这个问题。

Employers are interested in how you approach problems.

雇主们对你如何处理问题感兴趣。

临近；来临

As autumn approached, the plants and colours in the garden changed.

秋天临近，花园中的草木和颜色也发生了变化。

the approaching crisis.

步步逼近的危机

2、essential

绝对必要的;必不可少的;基本的

It was absolutely essential to separate crops from the areas that animals used as pasture.

将庄稼和放牧区分开绝对必要。

As they must also sprint over short distances, speed is essential.

由于他们也必须进行短跑，因此速度至关重要。

必需品;不可或缺之物

The flat contained the basic essentials for bachelor life.

那套公寓配有单身生活的基本必需品。

基本的;本质的；根本的

Most authorities agree that play is an essential part of a child's development.

大多数权威人士都同意，玩耍在孩子成长过程中起着非常重要的作用。

In this trial two essential elements must be proven: motive and opportunity.

在这次审讯中，必须证明两个基本因素：动机和时机。

（某学科的）基础，基本知识

the essentials of everyday life, such as eating and exercise.

饮食、锻炼等日常生活的要素

This has stripped the contest down to its essentials.

这就使比赛精简到最基本的环节。