Dinosaurs have been extinct for millions of years.

恐龙已经灭绝几百万年了。

In geologic time, a million years is recent history.

在地质学角度看来，一百万年属于近代历史。

Here it is better to say " better safe than sorry" .

在这里，说" 小心驶得万年船" 会更好些。

But that's what researchers have been deducing from a 70-million-year-old fossil clam.

但研究人员正是从7000万年的蛤蜊化石中推断出了历史。

Was it a)150,000 years ago? b)2 million years ago? or c)5 million years ago?

是在a)15万年？b)200万年？还是c)500万年？

Modern humans arose in Africa about 200,000 years ago.

现代人类大约在20万年出现在非。

They then spread across Europe and Asia sometime after 60,000 years ago.

然后在6万年的某个时候，他们传遍了欧。

Most species just last for a few million years.

大多数的动物 仅仅存在不到一百万年。

As for whether modern-day humans need to worry about this 405,000-year oscillation?

“那现代人类是否需要担心这种以40.5万年为周期的振荡？”

The fossil record shows that many species have endured for millions of years— so why shouldn't we?

化石资料表明很多物种曾生存百万年之久，凭什么认为人类不能？

You can't be too careful these days.

还是小心驶得万年船啊。

About 10,000 years ago, this crater was created by nature itself.

大约一万年，这个火山口自然形成。

After millions of years, in 2019, the great whites of Cape Town have vanished.

在这里生存了数百万年后，在2019年，开普敦海域的大白鲨消失不见了。

OK, so we'll start by going back thousands of years.

好的，那就让我们回到千万年之吧。

For most people over millions of years, that doesn't happen.

对于数百万年来的大多数人来说，这种情况不会发生。

Tens of millions of years later, we see another bird-like dinosaur enter the stage.

几千万年后我们看到了另一种似鸟的恐龙进入这个发展时期。

Millions of years of evolution later, you can see the difference.

数百万年的进化之后你可以看出差异 。

Earth would never be the same - at least not for millions of years.

地球将永远不会以一样——至少在几百万年内不会。

In 70 million years that's the most ridiculous thing I've ever heard.

七千万年来，这是我听过最荒唐的事。

We know that on earth, some bacteria can survive being frozen for millions of years.

我们知道, 在地球上, 一些细菌被冻结了数百万年后仍可以存活。