Mr. Brown was a farmer. One day he bought four donkeys(驴)in the market. He got on one of the donkeys and began to ride home. While he was riding home, he found that there were only three donkeys walking in front of him. "I want to know what happened," he said to himself"". I bought four donkeys. But now I see only three."Of course, he forgot to count the donkey he was riding.
When he got home, his sister met him in front of their house. "I see you bought strong donkeys. Did you buy them for a good price?""Yes, I am sure that bought four donkeys. But now it seems that I have only three ones."
At first his sister waited for him to smile. She thought he was joking. At last, she found that he was not. So she said,"You see only three, but I see five."