My best friend tells me that I am silly to be upset about this.

我最好的朋友说我为此事心烦太傻了。

《柯林斯英汉双解大词典》

I pretended to be upset.

我假装感到生气。

youdao

A lot of these people have reasons to be upset.

这些人大部分都有心烦不安的理由。

youdao

Mr.Bani Sadr argues the Iranian people have good reason to be upset with the results of the election: He insists that for a population that wanted to express itself and vote, this kind of fraud is unacceptable and thus people have taken to the streets to protest.

VOA: standard.2009.06.14

You seem to be upset.

你看起来有点沮丧。

It seems 实战 - SpeakingMax英语口语达人

I'm not going to name any company or industries, because they're all our customers and they'd be upset.

我在这里就不说它们的名字了，因为它们都是我们的客户，都会因此而沮丧。

斯坦福公开课 - 戴尔CEO-Michael.Dell谈创业和发展课程节选

Mr Clinton is also said to be upset that Mr Obama seldom asks his advice.

ECONOMIST: Barack Obama struggled this week to unite his party

So Chinese leaders, who used to be upset at the declining dollar, now cheer its weakness.

FORBES: Beijing To Bernanke: Bring On QE3, Fast

Hasan was scheduled to be deployed to Iraq "and appeared to be upset about that, " Sen.

CNN: Officials: Fort Hood shootings suspect alive; 12 dead