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

Traditional dance teachers did not welcome it because they thought it was not even a real dance and were quite sure about its demise but Swing has proved them wrong; it continues to be one of the world's most fun dances.

传统舞蹈老师不欢迎它，因为他们认为它甚至不是一个真正的舞蹈，并非常确定它会消亡，但摇摆舞证明他们错了；它仍然是世界上最有趣的舞蹈之一。

youdao

That is what one wants to be sure of... Wood is a pleasant thing to think about.

我们想弄清楚的也就是这个问题。木头是一件值得加以思索的愉快的事物。

youdao

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

VOA: special.2010.07.20

Now, I'm not sure what kind of video we're talking about, and I'm not sure if the lecture will be the internet when we're all done. But nonetheless I'm gonna call this the next big thing-the video internet .

呃，我不确定我们要谈关于什么样的视频,我也不确定当这个讲座全部结束时,还是不是关于网络，但尽管如此,我还是要叫它为下一重大事件，网络视频。

麻省理工公开课 - 媒体、教育、市场课程节选

The first thing I want to be sure was all students understand about the mechanics of the course and the best way to learn about that was to read very carefully the paragraphs at the bottom.

首先我想确认,大家都能明白这门课的授课形式,大家最好都去仔细阅读,刚发下去的课程大纲,请看这一页的底部。

麻省理工公开课 - 电影哲学课程节选

We'll probably discover more of these systems and we'll be able in a couple of years to be sure about this sort of diagnosis.

BBC: Kepler star trio find is mystery to astroseismologists

"Under-13s create a real problem because it is absolutely impossible in the current set of standards to be sure about the age of anyone because children will lie, " he said.

BBC: Dad of girl, 12, sues Facebook over her suggestive photos

The world now knows that America attacks only those countries that it can be fairly sure of defeating within about a month and with minimal casualties.

ECONOMIST: Was war warranted?