作为一名保护者，父母可通过拥抱与孩子接触。

The only sensible ends of literature are, first, the pleasurable toil of writing; second, the gratification of one's family and friends; and lastly, the solid cash.

Man should humbly face nature.

The best way to predict the future is to invent it.

历史总是由胜利者书写，但真相往往藏在失败者的沉默中。

The structure of the international system forces states to behave in certain ways, regardless of their internal characteristics.

NP中的每个问题都可以归约为可满足性问题，这是计算复杂性理论的基石。