That is what learning is. You suddenly understand something you've understood all your life, but in a new way.

抽象的目的不是模糊，而是创建一个新的语义层次，在这个层次上可以绝对精确。

The security dilemma is a fundamental feature of international politics, as states' efforts to increase their own security often decrease the security of others.

最好的想法往往来自最接近问题的人。

农业中的每个挑战都是创新和改进的机会。