Well, now one of the things farmers in history discovered is that it's very hard to do well as a farmer if all you do is grow the crops, because people normally don't use what you grow in the form in which you grow it.

关于农民我们在历史上能够得知的一件事是,当好农民很困难,特别是只种农作物的农民,因为人们一般不会将,你从地里种出来的东西留作种子

耶鲁公开课 - 古希腊历史简介课程节选