the hardest arithmetic to master is that which enables us to count our blessings.
世界上最难的算术题是如何清点我们的祝福。
according to legend, a young man while roaming the desert came across a spring of delicious crystal-clear water. the water was so sweet, he filled his leather canteen so he could bring some back to a tribal elder who had been his teacher.
据传说，一个年轻的男子在漫游沙漠途中看到一泉如水晶般清澈而可口的水。水的味道非常甜美，于是他灌满了他的皮水壶，这样就可以带一些回去，送给曾经是他老师的部落长老。
after a four-day journey he presented the water to the old man who took a deep drink, smiled warmly and thanked his student lavishly for the sweet water. the young man returned to his village with a happy heart.
经过四天的旅程，他把水呈献给老人。老人深饮一口，和蔼地笑了笑，并深切感激学生赠予他甜美的水。年轻人怀着愉快的心情回到了村庄。