英语听力：探索发现 2013-01-18 冰河新新州 Ice Age Oasis—16

 This triggered other dramatic changes. As sea levels dropped, so did the inland water tables. Florida's fresh water drained away through the porous¹ limestone² rock. Pools dried up and springs diminished. Florida was on the brink³ of drought. And animals would have had to travel to find food and water. So each year, mastodons would have migrated to the wetter regions. 

 

But in a few key places, water was still pushed up from underground as a spring, a vital oasis⁴ where wildlife would have converged⁵ from many miles around. Many animals would have fed on the surrounding vegetation and others come here to drink. And predators⁶ would have laid an ambush⁷ for the unwary. It's no wonder that so many fossil bones have been found on the bottom of these springs, clues that can open up a window on the ice age past. 

 

Bringing this evidence together, we can create a living picture of this region as it was then. We can now go back 13,000 years and see what a day around one of Florida's springs might have been like. 

 

Dawn on the southeast tip of ice age North America. On the banks of a spring-fed pool, the early grazers stir.

1 porous   

adj.可渗透的，多孔的

参考例句：

• He added sand to the soil to make it more porous.他往土里掺沙子以提高渗水性能。
• The shell has to be slightly porous to enable oxygen to pass in.外壳不得不有些细小的孔以便能使氧气通过。

2 limestone   

n.石灰石

参考例句：

• Limestone is often used in building construction.石灰岩常用于建筑。
• Cement is made from limestone.水泥是由石灰石制成的。

3 brink   

n.(悬崖、河流等的)边缘，边沿

参考例句：

• The tree grew on the brink of the cliff.那棵树生长在峭壁的边缘。
• The two countries were poised on the brink of war.这两个国家处于交战的边缘。

4 oasis   

n.（沙漠中的）绿洲，宜人的地方

参考例句：

• They stopped for the night at an oasis.他们在沙漠中的绿洲停下来过夜。
• The town was an oasis of prosperity in a desert of poverty.该镇是贫穷荒漠中的一块繁荣的“绿洲”。

5 converged   

v.（线条、运动的物体等）会于一点( converge的过去式 )；（趋于）相似或相同；人或车辆汇集；聚集

参考例句：

• Thousands of supporters converged on London for the rally. 成千上万的支持者从四面八方汇聚伦敦举行集会。
• People converged on the political meeting from all parts of the city. 人们从城市的四面八方涌向这次政治集会。 来自《简明英汉词典》

6 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》

7 ambush   

n.埋伏(地点)；伏兵；v.埋伏；伏击

参考例句：

• Our soldiers lay in ambush in the jungle for the enemy.我方战士埋伏在丛林中等待敌人。
• Four men led by a sergeant lay in ambush at the crossroads.由一名中士率领的四名士兵埋伏在十字路口。