The Earth takes twenty-four hours to complete one full turn or revolution of three-hundred-sixty degrees.

VOA: special.2010.07.14

Within 20 degrees of separation from you initial smile to the three people, the entire world will be smiling.

只需要20度的分隔,从你用笑容感染三个人开始，全世界就会笑起来。

哈佛公开课 - 幸福课课程节选

He says that in the Antarctic Peninsula, scientists estimate that climate change has caused temperatures to increase by two or three degrees Celsius over the past fifty years.

VOA: special.2009.06.03