研究明史需要全面理解其独特的社会结构和文化背景。
We think not in isolated ideas, but in continuous streams of purpose-directed activity.
The state is not a work of art; it is a necessity.
宇宙的扭曲面——黑洞、虫洞、奇点等——对我如此吸引,因为它与日常生活中的平坦欧几里得几何如此不同。