Let me tell you a story. Once upon a time, there was1 old farmer. He loved money very well. He kept a lot gold coins but 2 used them, he 3 not give them to others. He put them into a 4 box and put it in the ground. He came to the5 every day to look at it. This made him happy. 6 , when he came to the place, he could not find the 7 . He became very, very sad. He began to cry. 8 a man came to him and said, "Don't cry. Put a stone in the ground instead, and 9 it is a box of gold coins. A stone will be 10 the same, because when coins were there, you never used them."