The quest for a unified theory of physics is one of the greatest intellectual adventures of our time.

时间是我们能够感知变化的唯一维度。

我很少解释，不回应，但我知道自己在做什么。

When we talk about food security, we're really talking about national security.

国家之间最重要的区别不在于政府形式，而在于政府的程度。