求问雪莱的诗雪莱的无常,我在百度上搜到两个版本,一个是MUTABILITY. We are as clouds that

求问雪莱的诗
雪莱的无常,我在百度上搜到两个版本,
一个是
MUTABILITY.
We are as clouds that veil the midnight moon;
How restlessly they speed, and gleam, and quiver,
Streaking the darkness radiantly!—yet soon
Night closes round, and they are lost for ever:
Or like forgotten lyres, whose dissonant strings 5
Give various response to each varying blast,
To whose frail frame no second motion brings
One mood or modulation like the last.
We rest.—A dream has power to poison sleep;
We rise.—One wandering thought pollutes the day; 10
We feel, conceive or reason, laugh or weep;
Embrace fond woe, or cast our cares away:
It is the same!—For, be it joy or sorrow,
The path of its departure still is free:
Man’s yesterday may ne’er be like his morrow; 15
Nought may endure but Mutability.

一个是
The flower that smiles to-day
To-morrow dies;
All that we wish to stay
Tempts and then flies.
What is this world’s delight?
Lightning that mocks the night,
Brief even as bright.
今天还微笑的花朵
明天就会枯萎；
我们愿留贮的一切
诱一诱人就飞.
什么是这世上的欢乐?
它是嘲笑黑夜的闪电,
虽明亮,却短暂.
Virtue, how frail it is!
Friendship how rare!
Love, how it sells poor bliss
For proud despair!
But we, though soon they fall,
Survive their joy, and all
Which ours we call.
唉,美德!它多么脆弱!
友情多不易看见!
爱情售卖可怜的幸福,
你得拿绝望交换!
但我们仍旧得活下去,
尽管失去了这些喜悦,
以及“我们的”一切.
Whilst skies are blue and bright,
Whilst flowers are gay,
Whilst eyes that change ere night
Make glad the day;
Whilst yet the calm hours creep,
Dream thou–and from thy sleep
Then wake to weep.
趁天空还明媚,蔚蓝,
趁着花朵鲜艳,
趁眼睛看来一切美好,
还没临到夜晚；
呵,趁现在时流还平静,
作你的梦吧——且憩息,
等醒来再哭泣.
请问这是怎么回事?

这是翻译问题
这是雪莱的两首诗
第一首 标题是Mutability汉语翻译是 1转徙2变3无常
第二首 标题是The flower that smiles today汉语翻译是 1好花今日开2无常