英语听力：探索发现 2013-01-18 冰河新新州 Ice Age Oasis—16
时间：2018-12-27 作者：英语课 分类：探索与发现2013年
英语课
This triggered other dramatic changes. As sea levels dropped, so did the inland water tables. Florida's fresh water drained away through the porous 1 limestone 2 rock. Pools dried up and springs diminished. Florida was on the brink 3 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 oasis 4 where wildlife would have converged 5 from many miles around. Many animals would have fed on the surrounding vegetation and others come here to drink. And predators 6 would have laid an ambush 7 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
- 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
- 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
- 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
- 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
- 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》