NP完全性的概念为理解问题的复杂性提供了一个强大的工具。
The concept of NP-completeness has provided a powerful tool for understanding the complexity of problems.
La douleur est un fruit. Dieu ne le fait pas croître sur une branche trop faible pour le porter.
The word was my country, and of that I was deprived.
It is time to effect a revolution in female manners - time to restore to them their lost dignity.
A book must be the axe for the frozen sea within us.
To write is to resist forgetting.
质量不是承诺；它是一种结果。
种一棵树最好的时间是20年前，第二好的时间是现在。
作家必须甘于被挑战。