How can you be certain of this?

你怎么能这么确定？

My mechanical and reptilian logic are certain of it.

机械和爬虫逻辑相当确定。

Yes, I am. And how can you be certain of this?

是 你何以确定？

They were both English; my young friend was certain of this.

他们都是英国人。这一点这位年轻朋友十分肯定。

I can't be certain of what time I left the office.

不能肯定是什么时候离开办公室。

The telling clause here is Unless he is certain of doing well.

这里关键部分是“除非作者确认自己写得很好”。

Still, no one is certain of the actual identity of the model.

不，没有人能确定这位模特真实身份。

I've put water into the desert because I am certain of success.

把水引向沙漠中因为确信一定能成功。

You were certain of that, right? And not only was it a party school.

你们很确定这一点 不是吗? 不仅是个派对大学。

But our desire for quick answers may overpower the desire to be certain of their validity.

不们渴求快速解答可能远胜於确认它们可靠性慾望。

I was certain of the fact that this burning desire in her was unquenchable.

非常确定，这股希望在她心中不可撼动。

And you mentioned it to nobody else except your nephew, you're certain of that?

除了贵侄子外您没有对外人提起，您确定吗？

Yes, Merlin. I'm certain of it. If Arthur rides out against it, he'll die.

是，梅林。肯定。如果亚瑟要去对抗他，必死无疑。

He doesn't know why the computer was on, but he's certain of one thing.

他不知道电脑为什么会开机，但有一件事他是肯定。

He was certain of only one thing: he was dancing with a beautiful woman.

他正和一位美丽女人跳舞。

There just isn't enough continuous writing to let us be certain of what the symbols mean.

没有足够多连续文字，便无法确定这些符号意义，因此只能去推测他们对神灵或自然循环看法。

I think what we can be certain of is that both sides have deep reservations about this deal.

想们能确定是，方对这项协议均有所保留。

But there's one thing that I am certain of: hell and heaven exist inside of us, right now.

地狱和天堂现在就存在于们内心。

Now, you know, I am certain of that, beforehand'.

现在，你知道，事先就确定了这一点。

Indeed, I may say I am certain of it.

确， 可以说确信这一点。