The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.

农业中的每个挑战都是创新和改进的机会。

Don't sleep during the day at night, more or less what escape hide it. The day cannot solve the knot, the night slowly consumes.

我认为科学具有极大的美。实验室里的科学家不仅是一名技术人员：他还是一个站在自然现象面前的孩子，这些现象对他来说就像童话一样令人印象深刻。