题目内容：

A man and his friend were walking through the desert. During the trip they had a quarrel, and the man hit his friend in  1.  face. His friend was hurt, but 2.  saying anything, he wrote in the sand, “Today my best friend hit me.”

They kept on   3.  (walk) until they found a lake, where they decided  4.  (take) a bath. The man’s friend fell into the lake and was in a   5. (danger) situation, but the man saved him  6.  (immediate). After he came back to life, he wrote on a   7.  , “Today my best friend saved my life.”

The man  8. had hit and saved his best friend asked, “When I hurt you, you wrote in the sand and now, you wrote on a stone. Why?” His friend 9.  (reply), “When someone hurts us, we should write it down in sand, where wind can blow it away. However, when someone does something good for  10. (we), we must write it down in stone, where it can last for ever.”