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

因为在高海拔地区，空气要稀薄得多，所以氧气含量很少。

To increase your altitude or set off your dignified manner.

增加你的高度，衬托你的威仪。

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，使得飞须穿上航天服。

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。

As altitude increases, atmospheric pressure decreases.

随着海拔的升高，大气压降低。

Everest has the highest altitude on the planet.

珠峰则地球上海拔最高的山峰。

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，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。

The takeoff was accomplished, and they started gaining altitude.

起飞完成了，他们开始继续升高。

Each is at a different height, or altitude.

每个都处于不同的高度或海拔。

They get up into high altitude air currents.

它们可以进入高空气流飞。

That's when people's bodies tend to succumb to altitude sickness.

这时人们的身体往往会屈服于高山症。

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

这些云类型中哪个通常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.

这该地唯一一种生活在这种高海拔地区的动物。

And tour companies would need at least three years experience organizing high altitude expeditions.

旅游司需要至少有三年组织高峰探险的经验。

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

它们会由飞控制进低空飞，操作起来就像无人机一样。

Interestingly, their size and shape will vary with altitude and temperature.

有趣的，它们的大小和形状会随着海拔和温度的变化而变化。

As the altitude rises the highlands offer a cool haven.

随着海拔升高，这片高地提供了凉爽的栖息地。