轧棉机的发明是需求和观察的结果。
The invention of the cotton gin was the result of necessity and observation.
The study of nature is a perpetual joy.
最好的领导者是那些倾听多于说话的人。
The price of freedom is eternal vigilance.
Writing is the art of making the invisible visible.
The future depends on what you do today.
La justicia sin fuerza es impotente, la fuerza sin justicia es tiranía.
我越不确定，就越感到需要画画。