She set out the reasons for her resignation in a long letter.

她写了一封长信说明自己辞职的原因。

《牛津词典》

A well-written resignation letter can help you maintain a positive relationship with your old employer, while paving the way for you to move on.

一封写得好的辞职信可以帮你和前上司保持良好的关系，这样更有利于你将来的进步。

youdao

In his resignation letter, Haggis explained to Davis that, for the first time, he had explored outside perspectives on Scientology.

在自己的脱教信中，哈吉斯向戴维斯解释，这是第一次，他开始探究山达基之外的那些观点。

youdao

Despite early denials of wrongdoing from Eni head Paolo Scaroni, including a December 3rd letter calling for the resignation of Saipem leadership, the case continued to grow.

FORBES: Fresh Trouble for Algerian Oil and Gas

Goldman remains under scrutiny a day after a former employee very publicly ripped the firm for mistreating clients in a resignation letter published on the op-ed page of the New York Times.

FORBES: Goldman Shares Rebound Under Fire, Apple Readies New iPad (VIDEO)

This is not a resignation letter - I intend to hang on for dear life.

BBC: Should job-hogging over-50s all resign?