阅读下面一篇材料，从所给的A-G七个选项中，选出正确的选项填空，使短文通顺、内容完整。 People all over the world do shopping in supermarkets. Who decides what you buy in the supermarkets? 1._____________ When you go into the supermarket, you see shelves full of things.2.______________You pull a shopping cart and put the things you choose in it. If you hear soft and slow music, you may walk slowly. If you hear fast and loud music, you may walk quickly. 3._____________You walk slowly and have more time to choose things. Suppose you go to the meat department first. 4._____________The cheaper meat is at the other end of the meat department, away from where the customers enter. You have to walk by all the expensive meant before you find the cheaper one. 5.______________. That's some knowledge of supermarket science. Many supermarkets use such knowledge to make customers stay longer and buy more. A. Maybe you will buy some of the expensive meat instead of the cheaper meat. B. You walk between the shelves. C. That's why the supermarket plays slow and soft music. D. The manager of the supermarket knows where the customers enter the meat department. E. Do you decide or the supermarkets decide? F. You may feel a little tired to find the cheapest meat. G. You should learn some knowledge of supermarket science.