The difference in mental capacity between primitive and civilized man is not as great as is commonly supposed.
原始人与文明人在心智能力上的差异并不像通常认为的那样大。
The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.
如果你不经历艰难时刻，你就无法到达美好的时光。
I always knew I wanted to be a singer, and I never let anybody tell me I couldn't.
旅行对我来说，是恢复青春活力的源泉。