The first duty of the sovereign， that of protecting the society from the violence and invasion of other independent societies， can be performed only by means of a military force.

数学中的每一个问题都是学习新东西的机会。

经验只是我们给错误取的名字。

Sustainability is no longer an option; it's a necessity for the future of dairy farming.

So go ahead. Fall down. The world looks different from the ground.

译文：事前不研讨，遇变难以应对;军队不训练，作战难以取胜。强调未雨绸缪的重要性。

当你是一名赛车手时，你总是在寻找下一个弯道，下一个挑战。

我们都是一门手艺的学徒，没有人能成为大师。