题目

Henry found work in a bookstore after he finished middle school. He wouldn’t do anything but wanted to get rich. Mr King thought he was too lazy and was going to send him away. Henry was afraid and had to work hard.     It was a cold morning. It was snowing and there was thin ice on the streets. Few people went to buy the books and the young man had nothing to do. He hated to read, so he watched the traffic. Suddenly he saw a bag fall off a truck and it landed by the other side of the street.     “It must be full of expensive things, ”Henry said to himself. “I have to get it, o化简：（m3n）-2•（2m-2n-3）-2．