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。

《牛津词典》

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。

《牛津词典》

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。

《柯林斯英汉双解大词典》

He could not be sure of their support if he declared that the purpose of the war was to free the slaves.

VOA: special.2009.10.08

So, he started asking himself the question, "What can I be sure of?"

他首先问自己一个问题,"我究竟能够确信什么呢"

耶鲁公开课 - 心理学导论课程节选

But I'm sure you can easily see how these styrofoam balls could, in fact, be a mono layer of gold nuclei.

这个实验怎么工作的,我们先来做些计算，但我相信你们都已经。

麻省理工公开课 - 化学原理课程节选

Still, at any given point, Wikipedia visitors can't be sure of what they're getting.

CNN: Use with caution: The perils of Wikipedia

Although now plainly well placed to win the presidency, the Colonel cannot be sure of it.

ECONOMIST: The colonel rides on

That means it is possible to be sure of the paternity of a tadpole.

ECONOMIST: Animal behaviour