It is always good to have a problem that you cannot solve. It means you have something to work on.
有一个你无法解决的问题总是好的。这意味着你有事情要做。
The use of a program to prove the 4-color theorem will not change mathematics - it merely demonstrates that the theorem, a challenge for a century, is probably not important to mathematics.
The best way to predict the future is to create it.
最好的保护策略是将经济激励与生态效益结合起来。