There is nothing in the world so irresistibly contagious as laughter and good humor.

文章是用来阐明道理的。

无论是个人还是国家，只要生活节俭，就会繁荣昌盛；如果贪图享受，放纵欲望，那就会走向衰亡。

To find out what one is fitted to do, and to secure an opportunity to do it, is the key to happiness.

"Every word is a choice, and every choice is a sacrifice."

模糊集的概念提供了一种自然的方式来处理那些不精确性源于缺乏明确定义的类别成员标准的问题。