"Are you sure you can work out the problem yourself?" Peter asked me in disbelief.

“你确定你能自己解决这个问题吗？”彼得不相信地问我。

youdao

Are you sure you can handle it?

你确定你能处理这件事吗？

youdao

Are you sure you can see her soon?

你呆会儿肯定能和她见面吗？

youdao

"How do you make sure you are designing a system where you are going to constrain risk taking, you can prevent crises from spreading,and -- if a major institution managed itself to the edge of the abyss -- that we are able to put them out of their misery."

VOA: special.2010.04.16

These are just little things that can add up, so you just want to make sure you're on top of those.

这些小事情也会影响到你的总分，因此务必熟练掌握。

麻省理工公开课 - 化学原理课程节选

Then again, if you are not certain of something you can say "I'm not sure."

同样的，如果你对于一件事没有把握，你可以说“I'm not sure.”

I'm sure 课堂 - SpeakingMax英语口语达人

If you are not sure whether you can access the internet on your device, check with your mobile network provider.

BBC: News on your mobile

But you are sure - as sure as you can be sitting here - that Egypt will see a properly democratic, openly elected civilian government taking over by the end of the year say?

BBC: Transcript of Hatem Seif el Nasr interview

If you are an investor in a municipal bond fund that yields above average returns, you can be sure there are a few tobacco settlement bonds in the mix.

FORBES: Buffett Frets Over Municipals, So Should You