英语听力：自然百科 野性俄罗斯之西伯利亚 Siberia—5

 They can afford to--adult ravens¹ seem to lack natural enemies. Time for a quick brush-down and they're all done--well, almost.

 

Before man took his first step, ancient killers² roamed the earth. Unchallenged, they feared nothing, until Mother Nature intervened.

 

A northern coniferous forest zone called the taiga caps off Siberia. The largest forest in the world stretches seven million square kilometers. A northeastern section, Yakutia, the land of the horse people, brushes up against the Arctic circle. And though Yukut horses do roam here, they don't roam alone.

 

Through the hills of Yakutia comes a relentless³ army, reindeer⁴, a herd⁵ of a thousand strong. Built for cold weather, reindeer, or caribou⁶, have hollowed, tapered⁷ hair that traps heat next to their bodies. They haven't come here by chance. It's an annual roundup.

1 ravens   

n.低质煤；渡鸦( raven的名词复数 )

参考例句：

• Wheresoever the carcase is,there will the ravens be gathered together. 哪里有死尸，哪里就有乌鸦麇集。 来自《简明英汉词典》
• A couple of ravens croaked above our boat. 两只乌鸦在我们小船的上空嘎嘎叫着。 来自辞典例句

2 killers   

凶手( killer的名词复数 )； 消灭…者； 致命物； 极难的事

参考例句：

• He remained steadfast in his determination to bring the killers to justice. 他要将杀人凶手绳之以法的决心一直没有动摇。
• They were professional killers who did in John. 杀死约翰的这些人是职业杀手。

3 relentless   

adj.残酷的，不留情的，无怜悯心的

参考例句：

• The traffic noise is relentless.交通车辆的噪音一刻也不停止。
• Their training has to be relentless.他们的训练必须是无情的。

4 reindeer   

n.驯鹿

参考例句：

• The herd of reindeer was being trailed by a pack of wolves.那群驯鹿被一只狼群寻踪追赶上来。
• The life of the Reindeer men was a frontier life.驯鹿时代人的生活是一种边区生活。

5 herd   

n.兽群，牧群；vt.使集中，把…赶在一起

参考例句：

• She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
• He had no opinions of his own but simply follow the herd.他从无主见，只是人云亦云。

6 caribou   

n.北美驯鹿

参考例句：

• Afar off he heard the squawking of caribou calves.他听到远处有一群小驯鹿尖叫的声音。
• The Eskimos played soccer on ice and used balls filled with caribou hair and grass.爱斯基摩人在冰上踢球，他们用的是驯鹿的毛发和草填充成的球。

7 tapered   

adj. 锥形的，尖削的，楔形的，渐缩的，斜的 动词taper的过去式和过去分词

参考例句：

• The tail tapered to a rounded tip. 尾部越来越细，最后成了个圆尖。
• The organization tapered off in about half a year. 那个组织大约半年内就逐渐消失了。