题目

Shopping is a game with two teams—shoppers and retails (零售商). Here is the game plan you need. Bargains and Impulse (冲动) Shopping Limit the number of stores you go to. The more “legwork” you put in, the more you may feel the need to “reward” yourself for your effort. Don’t make friends with the sales staff. The more you interact (互动) with the sales staff, the more likely it is that you will buy something. This is because you feel like you don’t want to let down someone who has helped you. Leave your credit cards at home. Research shows people are willing to spend如图，菱形ABCD的对角线AC=24，BD=10，则菱形的周长L= ．