The mind is a dynamic system of adjustments.

The work of art is a whisper of the cosmos.

今天种植的每一棵树都是对更绿色明天的投资。

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

如果你独处时感到寂寞，这说明你没有和你自我成为好朋友。