"El verdadero viaje no es buscar nuevos paisajes, sino tener nuevos ojos."
The only way to avoid being miserable is not to have enough leisure to wonder whether you are happy or not.
释义:大丈夫立身处世,应当随机应变,怎能固执于一种方式?
两个物体的相互作用力总是大小相等,方向相反,同时出现或消失且作用于同一直线上。