They will not be met easily or in a short span of time.

VOA: special.2010.01.23

So one of the reasons there is a huge increase in life span is because people aren't dying of things that they would have in prior years.

寿命范围显著增长的一个原因是,人们不再死于,以前那些致死的东西

耶鲁公开课 - 生物医学工程探索课程节选

I've made a lot of really good friends in a really short time span.

在很短的一段时间里，我就交了很多好朋友。

斯坦福的奖学金 - SpeakingMax英语口语达人

They are serious and they are many. They will not be met easily or in a short span of time.

VOA: standard.2010.01.15