听力文本

Ripening fig trees, overhanging the water's edge, provide welcome food for shoals of hungry fish.
水边生长着高大的无花果树，为饥饿的鱼群提供美味食物
The commotion attracts dorado, known locally as the river tiger.
骚动引来了麻哈脂鲤，当地人称之为“河中之虎”
They patrol the feeding shoals looking for a chance to strike.
它们穿梭于觅食的鱼群中，找准机会发动进攻
And waiting in the wings, ready to pick off any injured fish, are the piranhas.
有些鱼则守在一旁等待，时刻准备攻击任何受伤的鱼，它们就是锯脂鲤
A feeding frenzy quickly develops.
它们的进食速率极快
Piranha can strip a fish to the bone in minutes.
锯脂鲤几分钟内便能将一条活鱼啃得只剩下骨架

Great numbers of fish sustain vast flocks of water birds.
大量的鱼养活着大批聚集的水鸟
The roseate spoonbill is just one of the 650 bird species found in the Pantanal.
粉红琵鹭是潘塔纳尔沼泽地中的650多种鸟类中的一种
They nest alongside woodstorks in colonies thousands strong.
它们将巢建在树干上，一群多达好几千只。
Spectacled caiman linger below, waiting for a meal to fall out of the sky.
眼镜凯门鳄在下面游荡，等着食物从天而降。

词汇解析

1.look for a chance 寻找机会
Therefore, successful learners do not wait for a chance to use the language; they look for such a chance.
因此，他们不会等到有了机会才去运用语言，相反，他们寻找机会。

2.wait in the wings 严阵以待
Obama had been pondering whether he should step to center stage or wait in the wings as the turbulent last months of the Bush Administration played out.
奥巴马思考过，他是应该站到舞台中间，还是在寒风中等待布什内阁应付完骚乱的最后一个月？

3.pick off 攻击；截取
The sniper picked off the enemy soldiers as they tried to leave their hut.
当敌人士兵企图离开营房时，狙击手将他们一个一个地瞄准射死。

视频及简介

淡水是我们最宝贵的资源，它决定了地球上生命的分布。同河流一起，从高高的山峰一路而降，直向大海，观看壮观的瀑布，在大峡谷里飞翔，在世界上最深的湖泊的冰雪下面探索野生的生命，见证动物行为的独特的、生动的一面：水獭和泽鳄将一决胜负。