介导疼痛的分子非常古老,揭示了这种感觉在进化中的深远根源。
In a time of universal deceit, telling the truth is a revolutionary act.
现代密码学的挑战不仅是确保通信安全,而且要以既高效又可扩展的方式实现。
A man knows when he is growing old because he begins to look like his father.