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.

它提醒我们要谨慎评估成功，不要低估运气的作用。

The magi, as you know, were wise men—wonderfully wise men—who brought gifts to the Babe in the manger. They invented the art of giving Christmas presents. Being wise, their gifts were no doubt wise ones, possibly bearing the privilege of exchange in case of duplication.