Ad sales have always gone up and down with the economy.

VOA: special.2009.03.21

There will always he suggests appear to be something ad hoc about the methods used in the study of politics.

主题允许多少精准性？我们如何得知,事情总有，他也提到,总有一些事是特别的。

耶鲁公开课 - 政治哲学导论课程节选