"In observational studies, we often have to rely on assumptions that are not directly testable."
女人了解她所爱的男人的脸,就像水手了解开阔的大海。
有些人有谈判的能力。这基本上是一个天赋的艺术,要么有要么就没有。
Sometimes the simplest melodies carry the deepest emotions.
Everything is what it is, and not another thing.