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.
You can't just sit there and wait for people to give you that golden dream. You've got to get out there and make it happen for yourself.
在数学中，提出问题的艺术必须比解决问题更有价值。
"The most important thing in science is not so much to obtain new facts as to discover new ways of thinking about them."
"The pursuit of excellence is a never-ending journey."
成功不在于你赚了多少钱，而在于你对人们生活的影响。
The more you invest in a bad relationship, the more it costs you.