英语听力：自然百科 探索世界奥秘之Wild Europe-Genesis (欧洲自然写真) Unit13（在线收听）

Wild Europe - Genesis 肇始之初- 13

As the sun beat down, something like 4,000 cubic kilometers of water evaporated from the Mediterranean surface every year. And with no Atlantic water to replenish it, the Mediterranean dried out. In just a thousand years, it became a desert basin of salt pans and caustic lakes. The rivers that once fed the Mediterranean cut deeper and deeper into the rock, chasing the dropping shoreline and forming a labyrinth of dramatic gorges.

Just a few million years ago, France's Rhone Valley must have looked more like the Grand Canyon. So intense was the heat in the basin that these waterfalls evaporated before they even reached the old seafloor. For tens of thousands of years, a natural dam between present-day Morocco and the Rock of Gibraltar held the waters of the Atlantic bay. The Mediterranean basin remained an almost lifeless expanse of salt, sand and parched earth. But as Africa pushed and pulled Europe's southern boundary, the pressures on the crust became unbearable. Rising tides weakened the land bridge and then the Atlantic burst its way over the precipice. So began the most gigantic flood ever. At its peak, enormous waterfalls a thousand times grander than Niagara thundered into the basin. More than 100 cubic kilometers of water gushed past Gibraltar every day.

words and expressions

replenish: To fill or make complete again; add a new stock or supply to:

补充：把…再装满或再备足；给…新添备料或供给

caustic: Capable of burning, corroding, dissolving, or eating away by chemical action.腐蚀性的：通过化学反应可被灼烧、腐蚀、销溶或蚀尽的

expanse: A wide and open extent, as of surface, land, or sky.

广阔：广阔的水面、陆地或天空

parched:炎热的

precipice:An overhanging or extremely steep mass of rock, such as a crag or the face of a cliff.

悬崖：悬崖或极其陡峭的岩石，如岩崖或悬崖壁