one day ,a boy had nothing to do,so he decided to play a trick with people.he taken a long rope ,then stopped a lady on the pavement and asked her to help him.he explained that he was doing a school project ,he was trying to measure the building ,but only one can not finished it ,so he needed some help.he asked her to hold one of the rope,so he can measured the building easily,and this take just for a few minites.the lady was glad to help the young boy .then she hold one end of the rope,the boy went around the corner .he asked another people to help him in the same way,then he went away and left the two people .the two peope could not see each other .the boy hid behind a febce and watched them .later ,the boy saw his friend ,and told his friend Ben this thing and laughed at them .at this time,the two people who were treated by him came up behind them ,they looked angry very much .the boy fleed at once .