Helium is the by product of millennia of radioactive decay from the elements thorium and uranium.

氦是钍和铀元素数千年放射性衰变的副产品。

For millennia the average person's stance toward providing for himself had been, ultimately I'm on my own.

几千年来，一般人对于养活自己的立场是，最终我要靠自己。

Once the soil has been removed by erosion, only the passage of centuries or millennia will enable new soil to form.

一旦土壤被侵蚀，新的土壤只有经过几个世纪或几千年才能形成。

We know that over the past millennia the climate has undergone major changes without any significant human intervention.

我们知道，在过去的几千年里，气候在没有任何大型的人为干预之下发生了剧大变化。

While it is unknown just how much of this is true, it is certainly known that silk cultivation has existed in China for several millennia.

虽然我们不知道这其中有多少是真实的，但可以肯定的是，丝绸栽培在中国已经存在了几千年。

Perhaps even earlier, there had emerged on the steppes of Inner Eurasia the distinctive types of pastoralism that were to dominate the region's history for several millennia.

也许更早的时候，在欧亚大陆内部的大草原上就出现了独特的游牧文化，这种文化主导了该地区几千年的历史。

If represented graphically, the curve for all these changes looks rather like that well-known hockey stick: with little change over millennia and a dramatic upswing over the past decades.

如果用图表进行展示的话，这些变化呈现出来的曲线很像大家熟悉的曲棍球杆：以往数千年都没什么变化，而在过去的几十年内却突飞猛涨。

In the years since the Pleistocene epoch, native species have adapted to the changing environmental there, plants, smaller animals, they have been evolving without megafauna for millennia.

在更新世以来的这些年里，当地的物种已经适应了那里不断变化的环境，植物，小动物，它们已经在没有巨型动物的情况下进化了几千年。

It's been disturbed for the first time in millennia.

这是千年来第一次被打扰。

Arching 275 feet and across 290 feet, Rainbow Bridge in the Utah desert has been a source of inspiration and wonderment for millennia.

拱高275英尺，跨度290英尺，犹他州沙漠里的彩虹桥一直是几千年来的灵感和奇迹的来源。

It's every archaeologist's dream to find a lost civilization, to make some huge discovery, to find artifacts no one else has laid a hand on in millennia.

每个考古学家的梦想都是找到一个失落的文明，做出一些重大的发现，找到千年来无人触及的手工艺品。

I'll report back in several millennia.

我的报告将追溯至数千年前。

We have occupied these lands for millennia.

我们占有这块土地已经有几千年了。

They were born just a few millennia too soon.

他们早生了几千年。

No new ice age is due for some millennia to come.

但新的冰河时期还不会在某个千年之年时到来。

And man has been tampering with nature for millennia.

而且人类几千年来一直在改造自然。

Diasporas have been a part of the world for millennia.

几千年以来移居群体一直是世界的一部分。

The history of bull fighting stretches back millennia.

斗牛的历史迄今已有一千多年了。

This is for the first time in more than five millennia.

这是五千多年以来的第一次。

Families are matters of millennia, far beyond a few generations.

家庭，事关千年，它远远超越了几代人。

Our cognitive biases have survived for millennia for good reason.

几千年来认知偏差一直存自有它存在的充分理由。

Taiji’s men have chased whales on Japan’s coast for perhaps millennia.

而太地人在日本沿海捕鲸的历史可能已经有上千年了。

But not all white dwarfs will spend many millennia cooling their heels.

不过并不是所有的白矮星都有耐性等上无数个千年。

The mink, by contrast, will remain at large for years, perhaps millennia.

相反的，貂也能自由过上数年，或许千年的太平生活。

Over thousands of millennia a mantle of sediment built up over its bones.

数百万年地幔沉积物堆积在（鲸）的遗骨上。

Over the millennia all manner of styles and materials have been used for shoes.

数千年来，各种造型和原材料用于制鞋。

The old ways began to change with foreign influence some two millennia ago.

这一节日传统在大约两千年前开始受到外来影响。

For millennia, our archipelago has been home to many currents of civilisation.

一千年以来，我们周围的群岛就是许多文明的家园。

The chart below shows a population-weighted history of the past two millennia.

下表展示了过去两千年以来按人口加权的历史。

Human beings have been seeking effective ways to deal with complexity for millennia.

几千年来，人类一直在寻找解决复杂性的有效方法。