Boundaries define us. They define what is me and what is not me. A boundary shows me where I end and someone else begins, leading me to a sense of ownership.

我是一个无可救药的浪漫主义者。

每一种化学结合完全且仅仅依赖于两种对立的力量，即正电和负电。

悲观主义者在每个机会里看到困难。乐观主义者在每个困难里看到机会。