People may not be sure about life on Mars until a sample of life is brought back.

人们可能不确定火星上是否有生命，直到一个生命样本被带了回来。

youdao

Be sure about the purpose of writing the feature story.

确定好写特写的目的。

youdao

There were many I didn't know, and others I couldn't be sure about because they were so covered in green parasites.

这里有许多我不认识的树，还有有一些树我没法确认，因为它们都覆盖在了密密麻麻的绿色藤蔓植物下。

youdao

But Professor Bedau says that nobody can be sure about the results of making new forms of life.

VOA: special.2010.07.20

I'm not at all sure there's anything more to be said about that passage, which I think lays it to rest.

我不确定这篇文章是不是,还要更多的讲解，就这样的吧。

耶鲁公开课 - 文学理论导论课程节选

Weird things, bad things can happen and so one of the lessons too that will be repeated throughout the course is to actually rigorously error check and make sure that you're always thinking about your user being a bad guy.

各种古怪的事情就会蜂拥而至,所以在这个课程中我反复强调,要一丝不苟地检查错误,你就当你的用户是个调皮捣蛋的家伙。

哈佛公开课 - 计算机科学课程节选

There is a lot she will not be sure about at the subsequent inquiry.

CNN: Books - Excerpt: 'Flint'

How can voters be sure about what Republicans really believe, other than the importance of winning elections?

FORBES: Republicans Need To Grow Up About Taxes

No one can be sure about the future course of the world economy, even a few months ahead let alone a year.

ECONOMIST: A bad time to be an ostrich