Because the air is substantially thinner at high altitudes there is substantially less oxygen.

因为在高海拔地区，空气要稀，所以氧气含量很少。

They get up into high altitude air currents.

它们可以进入高空气流飞行。

To increase your altitude or set off your dignified manner.

增加你的高度，衬托你的威仪。

The ICBM reached an altitude as high as 2,800 miles.

这枚洲际导弹到达了2800英里的高空。

It hits a top altitude of around 70,000 feet,forcing pilots to wear a spacesuit.

它要飞到70,000英尺的高度，使飞行员必须穿上航天服。

As altitude increases, atmospheric pressure decreases.

随海拔的升高，大气压降低。

But staying at that altitude will be tough.

但要继续站在这个高峰困难重重。

After it leaves China and the high altitude, the Mekong becomes wide, brown and warm.

当流出中国，流出高地后，湄公河就变宽，变暖了。

The rocket reached the desired altitude during its first test in 2009.

该火箭在2009年的第一次测试中达到了预期高度。

This helps the climbers acclimate to the increase in altitude.

这样有助于登山者适应海拔的上升。

Each is at a different height, or altitude.

每个都处于不同的高度或海拔。

Most people can only stay minutes at that altitude without extra oxygen supplies.

大数人在没有额外供氧的情况下只能在那个高度停留几分钟。

Which of these cloud types is typically found at the highest altitude?

这些云类型中哪个通常是在最高海拔处被发现的？

These spacesuits are crucial for those who are heading for super high altitudes.

这些宇航服对于那些正前往超高海拔地区的人们来说至关重要。

One of the only kind of animals living in this high altitude.

这是该地唯一一种生活在这种高海拔地区的动物。

These fighter jets are very automated when it comes to just holding altitude and heading.

当只需要保持高度和航向的时候，这些战斗机是高度自动化的。

Among them are requiring the climbers themselves to have training and experience at high altitudes.

其中包括要求登山者自己具备在高海拔地区的训练和经验。

They are pilot controlled, fly at low altitudes and operate like drones.

它们会由飞行员控制进行低空飞行，操作起来就像无人机一样。

At even more dizzying altitudes, so-called sprites can be observed.

在更令人眩晕的高度，可以观察到所谓的“精灵”。

As the altitude rises the highlands offer a cool haven.

随海拔升高，这片高地提供了凉爽的栖息地。