Lee Kyoung-su,a market analyst at Taurus Investment and Securities in Seoul, (Voice) He says markets are worried about the possibility of a second financial crisis, like the one that began in the United States last year.

VOA: standard.2009.11.27

Just like one second is some convention we use and one meter is some convention we use.

就像一秒是我们预先约定的,一米也是我们预先约定的

耶鲁公开课 - 基础物理课程节选