为了将关心转变为行动，我们需要发现问题，找到解决方案以及评估后果。但是世界的复杂性使得这三步都难于做到。
A healthy animal is the foundation of a healthy food chain.
预测未来的最好方法就是创造它。
我们都被自己制造的幽灵所困扰。
The P versus NP problem is one of the most important unsolved problems in computer science.
Trust is the expectation that arises within a community of regular, honest, and cooperative behavior, based on commonly shared norms, on the part of other members of that community.
