The United Nations peacekeeping force in south Lebanon has backed Israel's version of events following the most serious border clash in four years on Tuesday.

VOA: standard.2010.08.04

And so it really, not the course but the idea for the course, was an evolution three years four years ago, really, when I was involved in something called the Civic Values Task Force, which was started by Princeton Project 55.

所以说，不是这个课程,而是这个课程的设想，是在三四年前形成的，当时我参加了,公民价值专责小组，由普林斯顿大学55工程发起。

普林斯顿公开课 - 人性课程节选

He made a commitment to the nation's service members, in a refueling stop at Elmendorf Air Force Base on his way to visiting four nations in Asia.

VOA: standard.2009.11.13

The police force four years ago had a crude 'simulator' in the form of a wooden maze which was barely transportable.

BBC: News | Education | Pupils become virtual crime fighters

Barcelona, meanwhile, must score four to even force extra time against a Bayern defensive juggernaut that has allowed just 14 on its way to the Bundesliga title.

WSJ: The Secret of Germany's Success

It took years of focused effort among many nations to bring the NPT into force four decades ago and to sustain it as the most widely embraced nuclear agreement in history.

WHITEHOUSE: The White House