英语听力：探索发现 2012-09-09 长毛象王国 Mammoth—1

 21st century, North America, where people have reached even the remotest corners of the continent, and pushed back the boundaries¹ of modern technology. 

 

But it isn’t so long since humans first set foot here about 14,000 years ago. And back then, North America belonged to other creatures of the size to match this vast² land, giants whose lives are now lost in the shadows. 

 

Imagine if we could travel back in time to the end of the last ice age, long before the first city was born, to look through the eyes of the very first people, and experience a wild new world. 

 

In this series³, we will take you on a journey back into the past to build a picture how things were at the end of the last ice age, 14,000 years ago.

1 boundaries   

n.分界线( boundary的名词复数 )；范围；使球越过边界线的击球（得加分）；疆界

参考例句：

• Country boundaries are shown on this map as dotted lines. 这张地图上国界以虚线标出。
• The boundaries of that country were changed by a treaty. 那个国家的边界根据条约有所更动。 来自《简明英汉词典》

2 vast   

adj.巨大的，庞大的；大量的，巨额的

参考例句：

• Tom has made a vast improvement in his German.汤姆的德语有了很大的进步。
• China has a vast territory and a large population.中国地域辽阔，人口众多。

3 series   

n.连续；系列

参考例句：

• The students have put forward a series of questions.学生们提出了一系列问题。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。