听力原文：M: Hey Linda, did you get that letter about the new options for food service next year? W: Not yet. Are there a lot of changes? M: There sure are. Instead of paying one fee to cover all meals for the whole school year, we will now be able to choose how many per week we want and can contract for just that amount. We still have to pay for the whole year at the beginning. But we can choose to buy seven, ten, fourteen or twenty-one meals per week. They give you a card with the number of meals you get for a week marked on it. W: That's a big change Tom. And a complicated system. M: Yeah. But it will be much better for people who don't eat three meals a day, seven days a week in the cafeteria because they won't have to pay for meals they don't eat. W: So what's the deal for those who do eat at school all the time? M: It's better for them too. Because the more meals you contract for, the cheaper each one is. W: I see. It still sounds rather complicated. M: True. It took me several hours to figure it out. I decided to go with the ten-meal plan. W: Why is that? M: Well, I never eat breakfast and I often go away on weekends. So the ten-meal plan gives me lunch and dinner every weekday at a fairly low price. And I won't be paying for meals I don't usually eat. W: And what about the weekend when you are on campus? M: Well, there are often guests on campus on weekends. So they allow you to huy single meals on a walk-in basis on Saturdays and Sundays. The price per meal is much higher in that way. But I am away so much that it will still be less money for me to pay single prices on tile weekends rather than sign up for the fourteen meal a week plan. W: Oh, I guess I'll have to sit down and figure out my eatting pattern so 1 can get the best deal. What's the main feature of the new method of paying for meals?