The line between good and evil is permeable and anyone can cross it when pushed by circumstances.
善恶之间的界限是可渗透的，任何人在环境的逼迫下都可能跨越它。
I saw China embracing the world and vice versa.
生命中最要紧的事即是彼此。
The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.
石油的未来在于平衡经济增长与环境管理。