I said in the letter a most important thing.

我在信中讲了一件非常重要的事。

youdao

The most important thing is to reach an agreement and to avoid a trade war.

最重要的就是达成协议，避免贸易战。

《柯林斯英汉双解大词典》

"The most important thing is to be honest," she says, without the trace of a blush.

“最重要的是要诚实。”她说道，丝毫不脸红。

《柯林斯英汉双解大词典》

"I think the most important thing being a beaded jewelry designer is having patience."

VOA: special.2009.05.18

What do you think is the most important thing to teach students who learn English as a second language?

你觉得要教那些以英语为第二语言的学生，最重要的是什么？

教英语 - SpeakingMax英语口语达人

And success, as a fourteen years-old squash player, was the most important thing in my life.

成功对14岁的壁球手来说，是我生命中最重要的东西。

哈佛公开课 - 幸福课课程节选

Internships, paid or otherwise, are without a doubt the most important thing a college student can do to become a valuable potential hire when entering the job market sometimes more important than actually going to class.

FORBES: How To Get Your Dream Job Before Graduating College

Being a parent is positioned as the most important thing a person can do but is given little social or political support.

FORBES: Why Have Kids? Exposing The Motherhood Paradox

And I'm a big believer that the most important thing that a kid can learn in school is how to learn and how to think.

WHITEHOUSE: Your Interview with the President