The concept of a Turing machine is foundational to our understanding of computation.

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 risk war with one another.

所有老年人共有的一个大秘密是，你在七八十年里其实并没有改变。你的身体变了，但你一点也没变。这当然会引起很大的困惑。