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.
如果没有蝴蝶，没有毛毛虫，还会有谁来看我呢？你离我那么远……至于大动物，我才不怕呢，我有我的力爪啊。
战争不会在战斗停止时结束；它的回响会延续几代人。
The beauty of mathematics lies in its ability to describe the universe in the most elegant way possible.