时节不寒冷，就不会知道松柏挺拔且郁郁葱葱的；事情不危难，就不会知道君子每日都在持守信念。

States are rational actors that seek to maximize their relative power in order to ensure their survival in a competitive international system.

海洋生态平衡比短期经济利益更重要，我们要有长远眼光。