纪录片《我们的地球》 第73期 洞穴迷宫(12)

So far, more than 350 miles of underwater galleries in the Yucatan have been mapped.

人们迄今为止已绘制了350英里的尤卡坦半岛地下水系图

But still, nobody yet knows the true extent of this subterranean¹ water world.

但仍旧无人知晓这个地下水世界究竟有多大

And with good reason.

以及它形成的原因

Underwater caving is notoriously dangerous.

地下水洞是出了名的危险

When the nearest exit may be hundreds of metres or more away,

最近的出口可能远在几百米之外或者更远的地方

running out of air down here would be fatal.

在这里，耗尽氧气将是致命的

To avoid getting lost, divers² carry with them a spool³ of string.

为了避免迷路，潜水员必须随身携带一捆轴线。

It becomes their lifeline, literally⁴.

这成了它们的救生索，绝对如此。

The string also doubles as a measuring tape, a technique that has been used here in Mexico

这根线同时也是测量尺，在墨西哥的这个地方，这种科技被用来

to chart the largest underwater cave in the world, all 1 00 miles of it.

测绘世界上最大的地下水洞，全长达100多英里。

Cave exploration often requires you to push yourself through narrow gaps in the rock.

洞穴探险需要不时挤过一些狭窄的岩石缝隙。

Cavers call such places "squeezes".

洞穴专家称之为“瓶颈”。

1 subterranean   

adj.地下的，地表下的

参考例句：

• London has 9 miles of such subterranean passages.伦敦像这样的地下通道有9英里长。
• We wandered through subterranean passages.我们漫游地下通道。

2 divers   

adj.不同的；种种的

参考例句：

• He chose divers of them,who were asked to accompany him.他选择他们当中的几个人，要他们和他作伴。
• Two divers work together while a standby diver remains on the surface.两名潜水员协同工作，同时有一名候补潜水员留在水面上。

3 spool   

n.（缠录音带等的）卷盘（轴）；v.把…绕在卷轴上

参考例句：

• Can you wind this film back on to its spool?你能把这胶卷卷回到卷轴上去吗？
• Thomas squatted on the forward deck,whistling tunelessly,polishing the broze spool of the anchor winch.托马斯蹲在前甲板上擦起锚绞车的黄铜轴，边擦边胡乱吹着口哨。

4 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。