"Historically it's one of the most important parts of the period of World War II in France,the roundup - the rafle du Vel dHiv - is a symbol of collaboration between the French police and the German occupying authorities."

VOA: standard.2010.04.10

You have to discount something that's one period in the future by dividing it by 1+r.

你必须把未来一段时间内的资金通过,除以1+r来贴现

耶鲁公开课 - 金融市场课程节选