Iguassu Falls on the border of Brazil and Argentina 位于巴西和阿根廷边境的伊瓜苏瀑布
is one of the widest waterfalls in the world - 是世界上最宽的瀑布之一
They work together to drive shoals of fish into the shallows. 它们一起合作把鱼群赶到浅水区
To date over 3,000 species of their fish have been described - 据统计 被命名的鱼类已达到3000多种
more than in the whole of the Atlantic Ocean. 这比整个大西洋的鱼类种数还要多
The Amazon transports a billion tonnes of sediment a year, 亚马逊河每年会带来10亿吨的泥沙
sediment clearly visible at the mixing of the waters 泥沙使得河水交汇成为一道显眼的风景
On its way the system drains a third of South America. 全部流域面积达到南美洲的1/3
and its marine-like forests of sponges 再加上海底森林一般的海绵
80 percent of its species are found nowhere else on Earth, 湖里80%的物种 在地球上其它地方都不存在