【原文】Ten Principles of Economics 1: People Face Trade-off
【Trade-off】权衡；协调；交易；交换。A trade-off is asituation where you make a compromise between two things, or where you exchangeall or part of one thing for another.
【译文】十大经济学原理1：人们面临权衡
【原文】You may have heard the old saying, “There ain’t no such thing as a free lunch.” Grammar aside, there is muchtruth to this adage. To get somethingthat we like, we usually have to give up something else that we also like.Making decisions requires trading off one goal against another.
【old saying】老话、古话
【There ain’t no such thing as a free lunch.】等同于：There is no such thing as a free lunch。翻译为：天下没有免费的午餐。a free lunch，直译为：免费午餐。引申为：没有成本。
【adage】谚语；格言。An adage is something which people often say and which expresses ageneral truth about some aspect of life.
【译文】你可能听说过一句老话，“天下没有免费的午餐。”且不论文法问题，这句话很有道理。在我们喜欢的两个物品中，我们经常不得不为了得到一物而放弃另一物。做决策亦如此。
