They also know the gestures. Nearly 4,000 athletes have come from more than 80 countries to take part in the games this year.

VOA: standard.2009.09.10

When we look at this angular part, we see that it's always the square root of 1 over 4 pi, it doesn't matter what the angle is, it's not dependent on the angle.

当我们看这角向部分，可以看到它总是等于１除以４pai开根号，这和是什么角度没有关系，它和角度无关。

麻省理工公开课 - 化学原理课程节选

Germany currently has about 4,200 troops in Afghanistan, positioned mainly in the relatively-peaceful northern part of the country and focused on training missions.

VOA: standard.2009.11.09

Mr.Obama's June 4 speech in the Egyptian capital will take place as part of a trip that will include visits to Germany and France to commemorate the 65th anniversary of D-Day, when Allied forces stormed the beaches of Normandy during World War Two.

VOA: standard.2009.05.09