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.

如果你足够幸运与众不同，永远不要改变。

教育者必须是一位心理学家，以便理解儿童。

你不必聪明才能成功，你只需耐心和有纪律。