The spread of liberal democracy and the integration of the world economy have created a situation in which the major powers are no longer willing to go to war with one another.

The mind of the wise is an open book.

系统辨识的挑战不仅在于拟合数据，还在于提取有意义且可推广的模型。

I think of a hero as someone who understands the degree of responsibility that comes with his freedom.

我们不仅要关注技术的进步，还要关注用户的需求。