The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.
建筑师必须是诗人，但必须是建造的诗人。
The discovery of topological insulators has opened up a new frontier in condensed matter physics, where the interplay of symmetry and topology leads to novel quantum states of matter.
In the vastness of the universe, our problems seem small, yet our potential for understanding is limitless.