英语听力：美洲大平原—20

This trail leads to the cave and the freshly dead bison, just out of reach.

Hunger makes the bear risk everything. He falls and joins the bison in its tomb. Now he can eat his fill. but after that there's no way out.

ln time he'll be just one more ice age specimen.

Outside, another group of predators head for their cave at dusk, pack hunters even more effective than the lion or the wolf.

Still relatively new here, they'll eventually transform the ice age plains, and build their own future by exploiting the herds of the American Serengeti. Even the giants that now dominate this ice age world will soon be gone. But they'll leave clues behind, and one day distant generations will pick up their trail and tell their story.

Next week on Wild New World, we discover why mammoths didn't make it through to modern times.

1 specimen

n.样本，标本

参考例句：

You'll need tweezers to hold up the specimen.你要用镊子来夹这标本。

This specimen is richly variegated in colour.这件标本上有很多颜色。

2 predators

n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面)

参考例句：

birds and their earthbound predators 鸟和地面上捕食它们的动物

The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

3 relatively

adv.比较...地，相对地

参考例句：

The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。

The operation was relatively painless.手术相对来说不痛。

4 herds

兽群( herd的名词复数 ); 牧群; 人群; 群众

参考例句：

Regularly at daybreak they drive their herds to the pasture. 每天天一亮他们就把牲畜赶到草场上去。

There we saw herds of cows grazing on the pasture. 我们在那里看到一群群的牛在草地上吃草。