This is the present value of $1 in one time period, which I'm taking to be a year.

这就是一美元在一段时期内的现值,我只是将一美元持有一年

耶鲁公开课 - 金融市场课程节选

From 1983 to the present as you just said, the economy has a long period of smooth, robust expansion interrupted by two very mild recessions.

第二时期是从1983年至今，正如你所说，经济长时间处于,平稳强健的发展状态,而只出现了两次轻度衰退。

斯坦福公开课 - 经济学课程节选

Generally, if it pays c dollars for every period, the present value is c/r.

推广开来,如果在每段时期内支付c美元,那么它的现值就是c/r

耶鲁公开课 - 金融市场课程节选

If you looked at the antibodies that were present in the blood, for example, you would find that most of those antibodies are IgM during this initial period of antibody concentration rise.

如果你现在观察血液中存在的抗体,举个例子,在初次免疫的抗体浓度上升阶段,你将会发现大部分的抗体都是IgM

耶鲁公开课 - 生物医学工程探索课程节选