英语听力：探索发现 2012-11-14 美洲大平原 American Serengeti—8

 The Osage orange seeds were carried far across the plains, before being deposited, pre-packed in their fertilizer growbags, ready to take root.

 

As the ice age waned¹, the milder climate and the mixed vegetation meant the plains were able to support a range of wild life as diverse as Africa Serengeti today. There were at least five kinds of horse, including a wild ass², and another that resembled modern zebra, and North America's very own antelope—the pronghorn.  13,000 years ago, several different species roamed the plains. 

 

The pronghorn lived alongside other grazers still around today, including bison. This animal was common, too.  But now it would seem very out of place. 

 

Bigger than its modern relatives, the ice age camel was extremely hardy³, able to eat almost any kind of food. 

 

Elk⁴, like many ice age animals, survive almost unchanged. The rich parkland was ideal for these large deer. But one creature more than any other has remained a constant symbol of the plain since people first set foot here, the bison. 

 

Adult bison are formidable, two meters tall and weighing more than a ton. They too sheltered near the trees in winter, taking to the plains again in spring when new grass started sprouting⁵.

1 waned   

v.衰落( wane的过去式和过去分词 )；（月）亏；变小；变暗淡

参考例句：

• However,my enthusiasm waned.The time I spent at exercises gradually diminished. 然而，我的热情减退了。我在做操上花的时间逐渐减少了。 来自《用法词典》
• The bicycle craze has waned. 自行车热已冷下去了。 来自《现代汉英综合大词典》

2 ass   

n.驴；傻瓜，蠢笨的人

参考例句：

• He is not an ass as they make him.他不象大家猜想的那样笨。
• An ass endures his burden but not more than his burden.驴能负重但不能超过它能力所负担的。

3 hardy   

adj.勇敢的，果断的，吃苦的；耐寒的

参考例句：

• The kind of plant is a hardy annual.这种植物是耐寒的一年生植物。
• He is a hardy person.他是一个能吃苦耐劳的人。

4 elk   

n.麋鹿

参考例句：

• I was close enough to the elk to hear its labored breathing.我离那头麋鹿非常近，能听见它吃力的呼吸声。
• The refuge contains the largest wintering population of elk in the world.这座庇护所有着世界上数量最大的冬季麋鹿群。

5 sprouting   

v.发芽( sprout的现在分词 )；抽芽；出现；（使）涌现出

参考例句：

• new leaves sprouting from the trees 树上长出的新叶
• They were putting fresh earth around sprouting potato stalks. 他们在往绽出新芽的土豆秧周围培新土。 来自名作英译部分