A Raven and a Swan
乌鸦与天鹅

【注： raven 具体而言指乌鸦（crow）中的“渡鸦”】

A Raven, which you know is black as coal, was envious of the Swan, because her feathers were as white as the purest snow. The foolish bird got the idea that if he lived like the Swan, swimming and diving all day long and eating the weeds and plants that grow in the water, his feathers would turn white like the Swan's.
一只乌鸦通体漆黑如炭，却对一只天鹅心生嫉妒，只因那雪白的羽毛纯净如初雪。这愚鸟竟以为，若能效仿天鹅的生活方式——整日游水潜水，以杂草和植物为食——自己的羽毛也会变得如天鹅般洁白。

So he left his home in the woods and fields and flew down to live on the lakes and in the marshes. But though he washed and washed all day long, almost drowning himself at it, his feathers remained as black as ever. And as the water weeds he ate did not agree with him, he got thinner and thinner, and at last he died.
于是它离开栖息的林野，飞往湖畔沼泽定居。然而，尽管它终日冲洗羽毛，几乎溺毙水中，周身鸦羽依旧漆黑如初。并且它吞食的水草不合脾胃，日渐消瘦，终至命丧黄泉。

A change of habits will not alter nature.
积习可移，天性难违