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。