有一天我读了一本书，我的整个生活都改变了。

In international trade, a country should specialize in the production of goods for which it has a comparative advantage, and trade with other nations to maximize overall economic welfare.

路上丢失的东西没有人去捡拾，老百姓不敢乱取非分之财。并非形容民风淳朴，而是形容法律严明。