"And we want to make sure that NASA is going to be there for them when they want to take their journey."

VOA: standard.2009.07.20

So here, what I'd like you to do is identify the correct radial probability distribution plot for a 5 s orbital, and also make sure that it matches up with the right number of radial nodes that you would expect.

这里，你们要辨认,哪个是５ｓ轨道的正确概率分布，并且确保它和你们,预期的节点数相符合。

麻省理工公开课 - 化学原理课程节选

And also, you can't take land unless you make sure that there is as much land as possible left for other people to take as well.

同时，你不能掠夺他人土地，除非你保证,还有足够的土地留给其他人使用。

耶鲁公开课 - 公正课程节选

But the president has run into stiff opposition from conservative Republicans, and even moderate Democrats now believe it is likely that the president will have to settle for a compromise bill that is sure to disappoint his liberal supporters.

VOA: standard.2009.09.28

And that's very nice, because this allows me to be sure that my FOR loop is going to terminate.

因为这让我确信我的FOR循环是会终止的,因为只要集合是有限的。

麻省理工公开课 - 计算机科学及编程导论课程节选

"I do appeal to the candidates and to their campaigns and also to the voters to demonstrate the patience and calm that is required for the ECC to carry out its work in order to make sure that when we look back at the entire election process that we can say that it had the credibility that is required,"

VOA: standard.2009.08.24