A、On the top shelves. B、On the bottom shelves. C、On easily accessible shelves. D、On clearly marked shelves. C细节辨认题。短文中提到，利润高的商品所

A typical large supermarket offers around 17 000 to 20 000 items for sale and it wants to make sure that its customers see as many of them as possible. That’s why you’ll only find essential goods like bread, vegetables and meat in completely different parts of the store. Products with a high profit margin are always placed on shelves within easy reach of the customer, while lower margin items like sugar or flower are on the top or bottom shelves. Many people make shopping lists before they visit supermarkets. But even so, around 60% of all supermarket purchases are the result of decisions that are taken in the store. For this reason, supermarkets try to attract their customers by placing certain kinds of products next to each other. In the UK, beer will often be found next to items for babies because research shows that fathers of babies buy them on their way home from work and will buy beer at the same time. Research has also shown that this kind of impulse buy happens more frequently when no sales assistants are nearby. Supermarkets have made selling such a fine art that their customers often lose all sense of time. When interviewed, customers normally guess they’ve only spent half an hour in the supermarket even when they have been there for over 45 minutes. But that shouldn’t be too surprising. Any witty profitable supermarket knows that it should keep its clocks well hidden.
16. Why are essential goods displayed in totally different parts of the supermarket?
17. Where are goods with a high profit margin usually found?
18. What does the speaker say about supermarket goers?
19. What shouldn’t be too surprising according to the speaker?