原文视听

The gas given off contains two carbon isotopes.
释放出的气体包含两种碳同位素
The ratio of one to the other will indicate
两种同位素之间的比例可以说明
whether our ancestors were foraging in woods
我们的祖先是在森林中觅食
or going out to the grass-rich plains.
还是去绿草如茵的平原觅食
The result will reveal the sort of food eaten by ancient humans
结果将揭示古人类食用食物的种类
and the environment in which they lived.
以及他们所生存的环境
So far, Julia's research has revealed
迄今为止 朱莉娅的研究表明
that in the period leading up to the evolution of habilis,
我们祖先在进化成能人之前
there was a massive change in the lifestyle of our ancestors.
生活方式发生了巨大变化
The results tell us that our ancestors changed
结果告诉我们人类祖先
from a forest-orientated kind of diet and environment,
从森林导向的饮食起居方式
to one which concentrated on the grasslands.
向草原导向的生活方式转变
It's telling us that our ancestors ate
由此我们知道他们
animals which ate the grasses.
曾食用食草动物
But it's not just the tooth enamel
但不仅仅牙釉质
which shows a change in the diet of our ancestors -
显示了我们祖先的饮食变化
it's the tooth's shape itself which shows
牙齿形状本身也给出了
clues as to what they ate.
他们食用何物的线索

重点解释

The gas given off contains two carbon isotopes.释放出的气体包含两种碳同位素

give off散发(光、气味等)

The sun gives off heat and light.

太阳散发光和热。

Rotten eggs give off a bad smell.

臭蛋散发出难闻的气味。

The result will reveal the sort of food eaten by ancient humans结果将揭示古人类食用食物的种类

the sort of那种

He's the sort of person I really dislike.

他这种人我真不喜欢。

It was the sort of night when phantoms might walk.

这种夜晚正是幽灵出没的时候。

So far, Julia's research has revealed that in the period leading up to the evolution of habilis,迄今为止朱莉娅的研究表明我们祖先在进化成能人之前

lead up to导致； 引导； 作为 ... 的准备；一直通往（某处）

The events that led up to the murder were shown in a series of flashbacks.

酿成谋杀案的各个环节是通过一系列倒叙手法来表现的。

The report describes the negotiations that led up to the settlement.

这个报导记述了达成协议的那次谈判。