She closed her eyes tightly in a vain attempt to hold back the tears.

她紧闭双眼，却无法忍住眼泪。

《牛津词典》

It was a vain attempt to shift the responsibility for the murder to somebody else.

把这项谋杀的罪责转嫁于他人是徒劳之举。

《柯林斯英汉双解大词典》

The drafting committee worked through the night in a vain attempt to finish on schedule.

起草委员会徒劳地通宵工作想按期完成工作。

《柯林斯英汉双解大词典》

It is rather for us to be here dedicated to the great task remaining before us that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion that we here highly resolve that these dead shall not have died in vain that this nation,under God, shall have a new birth of freedom and that government of the people, by the people,for the people, shall not perish from the earth."

VOA: special.2009.11.12

And it's not just the accent of "Ain," "Quatre-vain" Or "Enfain" Instead of enfin-- it's a whole language.

而且不光是那种"俺"的口音,"把十"或者"嗨子"而不是孩子,完全是另一种语言

耶鲁公开课 - 1871年后的法国课程节选

This other man I had dreamed A drunken, vain-glorious lout.

我曾认为这另外一个人,是爱好虚荣，粗鄙不堪的酒鬼。

耶鲁公开课 - 现代诗歌课程节选

To say that Congress may withdraw or ignore that pledge is to assume that the Constitution contemplates a vain promise, a pledge having no other sanction than the pleasure and convenience of the pledgor.

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Walking through the halls for two hours was like marching through a desert, searching in vain for a flowing spring of argument or works that would enliven my sense of the period.

WSJ: Light Years: Conceptual Art and the Photograph, 1964-1977 | Snapshot of a Movement | By Richard B. Woodward

The members of the group, which includes an urbane young doctor, a vain and verbose prosecutor, a Gogol-esque clerk with a laptop computer, and a punctilious military officer standing guard, grow increasingly irritable as they slog through lonely and uninviting terrain.

NEWYORKER: Once Upon a Time in Anatolia