对于系统，翻版的模拟是在控制图中添加一个创建循环的边，而不仅仅是一个附加节点。
For systems, the analogue of a face-lift is to add to the control graph an edge that creates a cycle, not just an additional node.
In economics, as in life, the answers are often more nuanced than they first appear.
The poet is the voice of the silent universe.
Every new planet we find is a step closer to answering the age-old question: Are we alone in the universe?
出自汉·桓宽《盐铁论·疾贪》。贪婪卑鄙的风气源自处于上位的统治者，而不在下层民众；对民众的教育、对国民素质的改良在于执政者的措施是否得当，而不在于人民自身的素质。
商业中最危险的一句话是"我们一直都是这样做的"。
那些不能说“不”的人，也无法真正地说“是”。
维护程序的最好方法是维护它。