英語聽力：美洲大平原-9

Bison calves are born in summer and can run within a few hours of their birth. They have no choice. The herd won't wait in its eternal quest to find new grazing.

Smaller grazers are still found here, too. But they stay put instead of wandering the plains. Prairie dogs inhabit rambling subterranean towns that stretch tens of square miles. These highly social creatures stay within a short dash of their door, ready to retreat from predators or by weather. It’s always maintenance work to do, but major renovations have to wait until after rain when the soil is soft. All this working and re-working helps the land recover from the impact of so many bigger feet and appetites.

At summer's end, male bison help to move the sun-baked soil as the rutting season starts. They roll in dust and paw the ground to try to dominate their rivals. The dust bath also helps to dislodge irritating insects.

A prairie dog colony is usually surrounded by short, nutritious6 grass, thanks to the many teeth and toe. This constant grazing stimulates fresh growth and also keeps the field of vision clear for spotting predators. Larger neighbours are attracted to these burgeoning meadows, just as they were 13,000 years ago.

1 calves

n.(calf的復數(shù))笨拙的男子，腓;腿肚子( calf的名詞復數(shù) );牛犢;腓;小腿肚v.生小牛( calve的第三人稱單數(shù) );(冰川)崩解;生(小牛等)，產(chǎn)(犢);使(冰川)崩解

參考例句：

a cow suckling her calves 給小牛吃奶的母牛

The calves are grazed intensively during their first season. 小牛在生長的第一季里集中喂養(yǎng)。 來自《簡明英漢詞典》

2 herd

n.獸群，牧群;vt.使集中，把…趕在一起

參考例句：

She drove the herd of cattle through the wilderness.她趕著牛群穿過荒野。

He had no opinions of his own but simply follow the herd.他從無主見，只是人云亦云。

3 rambling

adj.[建]凌亂的，雜亂的

參考例句：

We spent the summer rambling in Ireland. 我們花了一個夏天漫游愛爾蘭。

It was easy to get lost in the rambling house. 在布局凌亂的大房子里容易迷路。

4 subterranean

adj.地下的，地表下的

參考例句：

London has 9 miles of such subterranean passages.倫敦像這樣的地下通道有9英里長。

We wandered through subterranean passages.我們漫游地下通道。

5 predators

n.食肉動物( predator的名詞復數(shù) );奴役他人者(尤指在財務或性關系方面)

參考例句：

birds and their earthbound predators 鳥和地面上捕食它們的動物

The eyes of predators are highly sensitive to the slightest movement. 捕食性動物的眼睛能感覺到最細小的動靜。 來自《簡明英漢詞典》

6 nutritious

adj.有營養(yǎng)的，營養(yǎng)價值高的

參考例句：

Fresh vegetables are very nutritious.新鮮蔬菜富于營養(yǎng)。

Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鳥發(fā)現(xiàn)花蜜和花粉是很有營養(yǎng)的。

7 stimulates

v.刺激( stimulate的第三人稱單數(shù) );激勵;使興奮;起興奮作用，起刺激作用，起促進作用

參考例句：

Exercise stimulates the body. 運動促進身體健康。 來自《簡明英漢詞典》

Alcohol stimulates the action of the heart. 酒刺激心臟的活動。 來自《現(xiàn)代英漢綜合大詞典》

8 burgeoning

adj.迅速成長的，迅速發(fā)展的v.發(fā)芽，抽枝( burgeon的現(xiàn)在分詞 );迅速發(fā)展;發(fā)(芽)，抽(枝)

參考例句：

Our company's business is burgeoning now. 我們公司的業(yè)務現(xiàn)在發(fā)展很迅速。 來自《簡明英漢詞典》

These efforts were insufficient to contain the burgeoning crisis. 這些努力不足以抑制迅速擴散的危機。 來自辭典例句