You all know why I am here. So I won't waste time on preliminaries.

你们都知道我为什么在这里。所以我就不浪费时间讲客套话了。

《柯林斯英汉双解大词典》

You all know why I am here, so I won't waste time on preliminaries.

你们都知道我为什么来这儿，因此我就不浪费时间作介绍了。

《柯林斯英汉双解大词典》

After walking onto the stage, she began to speak, "I know you have been laughing behind my back for years. Today I have a great chance to make you all laugh in front of me. That's why I am here."

走上舞台后，她开口说：“我知道你们在背后嘲笑我好多年了。今天我有一个很好的机会让你们在我面前笑。这就是我在这里的原因。”

youdao

She gave them a chance to choose," "This is why I am here, this why so many tens of thousands of people are here, because we want to show Saylan we appreciated her, we love her and despite all the work she has done she was treated as a guilty person by the state, and we do not approve of that."

VOA: standard.2009.05.20

What's my purpose? Why am I here?

我的目的是什么？我为什么在这里？

哈佛公开课 - 幸福课课程节选

"I never done it in my life - I don't,know kind of hard, that's why I am still here - unemployed."

VOA: standard.2010.05.15

My neighbors, she said, I must tell you why I am here.

NEWYORKER: Magda Mandela

That is why I am here, every day.

BBC: Owner vows Marriott will rise again

That's why I am here.

WHITEHOUSE: President Obama Addresses Council of La Raza