The challenge of modern cryptography is not just to secure communication, but to do so in a way that is both efficient and scalable.

书籍是最安静且最恒久的朋友。

经过不断改善自己的动作，幼儿从独立活动中获得喜悦。

衡量一个领导者的真正标准是他们在充满挑战的时期如何应对。