“丑小鸭变白天鹅”用英语怎么说？

Ugly duckling has grown into a swan
Form ugly ducking to swan

an ugly duckling(that has been)transformed into a beautiful swan.

“Duck will swan some day。”
我个人觉得，那个老外的话，把one换成some要好些。

The ugly duckling grows beautiful.

The ugly duck duckling turns into a swan

正确的答案是: The ugly duckling bleaches the swan