题目

       My parents ran a small restaurant in Seattle. It was open twenty-four hours a day, six days a week. And my first real job, when I was six years old, was   36   the diners’ shoes. My father had done it when he was young, so he taught me   37   to do it well, telling me to   38   to shine the shoes again if the customer wasn’t   39  .        I was proud of working in the restaurant   40   I was also working for the good of the family. But my father   41   said that I had to meet certain standards to be part of the team. I   42   to be o李大伯要在墙边围一块长方形地养鸡，长18米，宽12米．这块地一面靠墙，另外三面用篱笆围．有两种围法可以选择（如图）．哪一种围法用的篱笆少些？只要多少米？