[单项选择]They are (20) along the major roads throughout the Northeast. Form the parking lots, they look like railroad or trolley cars, but the cheery curtains in the windows, the flower boxes on the window sills, and the "Come on in, we’re open" (21) on the doors (22) something different. These are the diners, where eating is a (23) restaurant experience.
The first diners appeared almost one hundred years ago. (24) they were horse-drawn wagons filled with sandwiches, hot dogs, desserts, and coffee for people who wanted to eat (25) after 8:00 p. m. Many restaurants were already closed (26) that hour, but the diner stayed open. (27) earning the nickname, "night owl"
It was not until 1897, (28) , that the trolley design of the diner became popular. When Boston, Philadelphia, and New York City (29) their horse-drawn trolleys with modern electric cars, the abandoned models were bought by (30) merchants for 15 or 2