计算复杂性理论的发展向我们展示了并非所有问题都是平等的。
"You can't go back and change the beginning, but you can start where you are and change the ending."
你无法回到过去改变开头,但你可以从现在开始改变结局。
In the wild, you learn to appreciate the little things. They often make the biggest difference.
煤炭的未来取决于经济增长与环境保护之间的平衡。