He seemed so sure of his decision, how could he flip-flop so dramatically now?

他似乎对自己的决定非常肯定，现在怎么会戏剧性地改变立场呢？

Are you sure of what you've said?

你确定你刚才所说的话吗？

Indeed, I am sure of it.

是的，我敢肯定。

"You may be sure of that," said the hair-comb.

“你可以相信我的话。”梳子说。

So, as I said, not sure of numbers but of course we won't go over the maximum of 100.

所以，就像我说的，我们不确定具体的人数，但肯定不会超过一百人的上限。

She seems very sure of herself.

她好像十分自信。

I hope you are sure of your facts.

我希望你能肯定你说的都是事实。

You're always sure of a warm welcome there.

到了那里你肯定会受到热烈欢迎。

One thing I am sure of was that she was scared.

有一点我可以肯定的是她被吓坏了。

They scored another goal and made sure of victory.

他们又进了一个球，这就赢定了。

England must win this game to be sure of qualifying.

英格兰队必须拿下这场比赛才能确保获得资格。

One should never criticize if one is not sure of one's facts.

一个人如果对自己掌握的事实没有把握，就绝不该随便批评。

I'd never seen him like this, so sure of himself, so in command.

我从未见过他像这样，如此自信，如此得心应手。

England must win this game to be sure of qualifying for the World Cup.

英格兰队必须拿下这场比赛才能确保获得世界杯的参赛资格。

I'm not sure of the exact relationship between them—I think they're cousins.

我不太清楚他们之间的确切关系—我想他们是表亲。

She was no longer sure of her position. Apropos of that, it was clearly time for more persuasion.

她对自己的立场不再胸有成竹。谈及此，显然正是做更多说服工作的时候。

A lot of people think that it's better to pay for their education so that they can be sure of getting quality.

很多人认为最好是自己掏钱受教育，为的是能肯定得到高品质的教育。

If one of your friends sends you a message to borrow money on the Internet, you'd better phone him directly first to make sure of that.

如果你的一个朋友在网上给你发信息借钱，你最好先直接给他打电话确认一下。

The waiter made sure of it.

侍者确认了这一点。

Wendy was sure of it.

温迪对此很有把握。

She'll never get along with him, I am sure of that!

她绝对不会和他和睦相处的，我敢肯定！

A good plan helps you to make sure of your success in study.

一个好的计划有助于你在学习上获得成功。

Bcause we aren't sure of the causes for starfish population increases, it's difficult to prevent them.

因为我们不确定海星数量增加的原因，所以要预防就很难了。

She always attends to her own serious business herself, as then she is sure of having it done properly.

她总是亲自料理自己的正经事，因为那时她肯定能把它做好。

The researcher noted that the dolphin is quite eager to press the paddle when it was sure of the answer, but exhibited hesitation during difficult trials.

研究人员注意到，海豚在确定答案时会很着急地按下踏板，但在难度高的测验中则表现出犹豫。

It is said she is quite sure of success.

据说她很有成功的把握。

Are you sure of it?

这事你拿得稳吗？

She was sure of his honesty.

她信任他的诚实。

We have to be sure of that first.

我们得确信这是第一位的。

You: Branch? I'm not sure of its name.

你：哪个分支？我不能确定它的名字。