Natural experiments can provide valuable insights into economic questions.
我们今天种下的每一棵树都是对明天的承诺。
The beauty of life lies in the details we often overlook.
The power of human cognition comes from its ability to generalize.
世界上充满了自童年以来从未以开放的心态面对开放门户的人。
可持续性不再是可选项,而是当今世界生存的必要条件。