You will be notified by letter.

将用信函通知你。

《牛津词典》

Your job is to group them by letter and put them in numerical order.

你的工作是把它们按字母编组，再把它们按数字顺序排序。

《柯林斯英汉双解大词典》

I will contact you by letter.

我会给你写信联系的。

《牛津词典》

The sign is formed by a line across the right foot of the letter "R."

VOA: special.2009.03.22

Here's a copy of a letter to Pound by Yeats when they were both living in London.

这有一份叶芝写给庞德的信,他们当时都住在伦敦。

耶鲁公开课 - 现代诗歌课程节选

Ephesians was written by a different disciple of Paul, and he was using as his model for a Pauline letter the actual letters of Paul, or at least some of them that he possessed and knew of.

以弗所书则由保罗的另一信徒执笔，他伪造保罗的书信,模板是保罗的书信，或者他所持有的一些保罗的书信。

耶鲁公开课 - 新约课程节选

On Dec. 15, 2010, the agency informed him by letter that he had been granted benefits.

WSJ: Backlog of Social Security Disability Cases Leaves the Terminally Ill Waiting

When encountering an unknown word in kindergarten, we were told to sound it out, understanding it letter by letter.

FORBES: American Political Economy Is No Different From English Language

Explorer Sir Ranulph Fiennes has pleaded guilty by letter to speeding on the A9 in the Highlands last year.

BBC: Sir Ranulph Fiennes pleads guilty to speeding charge