That will,by necessity, need more troops, not only for the training, but for the mentoring in the field.

VOA: standard.2009.09.29

I mean, it's kind of a necessity for a lot of students, myself included, to have these jobs

我的意思是，对于大多数学生而言，
也包括我在内，做这些工作是很有必要的，

再没时间也要挤出来 - SpeakingMax英语口语达人

Hobbes, as we see, sometimes writes as a sort of scientist or proto-scientist for whom nature and one supposes the laws of nature operate with the same kind of necessity as the laws of physical attraction.

霍布斯有些时候,像科学家或者原科学家一样写作,对他来说，自然和自然法,与另一种必需法则,即物质吸引的法则共同作用。

耶鲁公开课 - 政治哲学导论课程节选

"Our emphasis in Canada for some time now,particularly since we extended our mission, has been the necessity of seeing the Afghan government accept and be able to handle greater responsibility for the day-to-day security of that country,".

VOA: standard.2009.09.16

Whereas for me, living outside of London, it's kind of, more of a necessity.

然而，对我来说，住在伦敦市区外面，它更像是一个必需品。

公共交通更方便 - SpeakingMax英语口语达人

"I am convinced, from my conversations with General Stanley McChrystal and I'm grateful to him for the time he gave me there and even on the telephone since he understands the necessity of conducting a smart counterinsurgency in a limited geographic area,".

VOA: standard.2009.10.26