地租是由土地的肥沃度和位置所决定的。
那下面发生的事情,跟他们说的完全不一样。
数学证明的优雅在于它的简洁和清晰。
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.
解释:割地给秦国(来求得暂时的安稳),就好像抱着木柴救火一样,木柴烧不不完,火就不会灭。
Change starts with a single step, but it takes a collective effort to make it lasting.