Public theaters during this time were usually three floor levels high and were built around a stage area where the actors performed.

VOA: special.2010.01.06

When people study stereotypes they often make certain distinctions between three levels of stereotypes and this is nicely summarized here.

当人们研究刻板印象时,他们通常会区分,三个层次的刻板印象,这里已经清楚地总结起来了。

耶鲁公开课 - 心理学导论课程节选

And I mentioned three reason why we want to shift this pendulum despite the fact that there are rising levels of depression around the world, on college campuses in United States,China,Australia,UK.

我提过三个原因,关于为什么要改变这个比率,尽管世界上越来越多人抑郁，遍布美国，中国，澳大利亚，英国所有大学。

哈佛公开课 - 幸福课课程节选

In all three of America's biggest cities, murder rates have fallen to their lowest levels since the 1960s.

VOA: special.2009.01.12

Prices in Phoenix,Arizona, are now fifty percent below their highest levels of three years ago.

VOA: special.2009.05.08

The study found that almost three-fourths of the brands had dangerously high levels of lead.

VOA: special.2009.08.31

The team predicted sea levels would rise by about three meters.

VOA: special.2009.06.03