听下面一段独白，回答以下小题。
【小题1】What is the main idea of this passage?

A．How you decide what to buy in a supermarket.

B．How a supermarket makes people spend more.

C．Who decides how much to spend in a supermarket.

【小题2】Why does the food that everybody must buy spread all over the store?

A．To provide a good service.

B．To lead customers to all sections of the store.

C．To make it easy for customers to locate the food.

【小题3】How much do people spend after they have been in a store for 30 minutes?

A．1,500 cents in total.

B．40 cents each minute.

C．Five dollars each minute.