Sustainability is not an option, it's a responsibility.
现代国家的特点是其能够有效地集中和使用权力。
The arithmetic of L-functions is a key to unlocking the secrets of number theory.
夜晚并没有隐藏世界;它揭示了另一个世界。
合同本质上是不完全的,因为不可能预见所有未来的偶然事件。
Every man is guilty of all the good he did not do.