States are inherently aggressive and expansionist because they exist in an anarchic international system where there is no higher authority to keep them in check.

RNA干扰是一个迷人的过程，它为理解基因调控开辟了新的途径，并具有潜在的治疗应用。

尘世存在的意义，并不像我们习惯于认为的那样，在于繁荣昌盛，而在于灵魂的滋长。

小说家的任务是唤醒读者的同情，让读者关心。