The study of L-functions is a window into the hidden structure of numbers.

林业实践的创新是平衡经济增长和环境保护的关键。

饥饿和贫困是世界上许多动荡和苦难的根本原因。

Challenges are what make business interesting; overcoming them is what makes it rewarding.

二手车市场是信息不对称的经典例子。