We need to write a thank-you letter.

我们需要写作一封感谢信。

He decided to send her a thank-you letter.

他决定送给她一封感谢信。

She showed her appreciation by sending a thank-you note.

她通过寄送感谢信表达了她的感激。

On Father's Day, I wrote a thank-you letter to my dad.

父亲节那天，我给爸爸写了一封感谢信。

You may not like them, but at least you don't have to write her a thank-you note.

你可能不喜欢它们，但至少你不必给她写感谢信。

S writing thank-you letters, it's not writing thank-you letters.

是写感谢信，是不写感谢信

Sending a thank-you note is a must.

发一封感谢信是必须的。

In response to their hospitality, we wrote a thank-you note.

为回报他们的热情,我们写了一封感谢信。

And the formal thank-you letter after the interview?

那么，应聘者要不要在面试后发一封正式的感谢信呢？

In response to their hospitality, we wrote a thank - you note.

为回报他们的热情, 我们写了一封感谢信.