Food is less expensive in a cafeteria , because you serve yourself .   How to do it ?   Just pick up a tray , then put a knife , a fork , a spoon and a paper napkin on it and stand in the line .   How long will it take to reach the buffet ?   Not long , because people rush for lunch .   The line sure does move fast .   Tell the man behind the counter what you want .   OK . I like that green vegetable but I don't know how to call it . 