The progress of science is not only measured by the accumulation of knowledge, but also by the ability to ask new questions.
科学的进步不仅通过知识的积累来衡量，还通过提出新问题的能力来衡量。
The concept of NP-completeness has provided a powerful tool for understanding the complexity of computational problems.
We are all haunted by the ghosts of our own pasts, and sometimes, by the ghosts of others.
The only real voyage of discovery consists not in seeking new landscapes, but in having new eyes.