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。