A、To warn of dangers. B、To explain traffic regulations. C、To wake up drivers who are falling asleep. D、To give directions. DSome

M: I’m sorry I’m late, Cindy.
W: That’s all right, Joe. My house isn’t that easy to find. But you know, you wouldn’t have gotten lost if you had a "smart" car.
M: A smart car? What’s Bat?
W: I just read a magazine article about some new technology that can make a car smart. One device is a computerized map display and a synthesized voice, you must enter the address where you want to go, and the voice tells you how to get there, street by street.
M: Hey, that’s just like my brother. He never gets lost, and he’s always telling me the best route. So what else will smart cars be able to do?
W: Well, the article said that they’ll be equipped with radar warning systems that will warn drivers if they’re getting too close to other cars with an alarm signal, and they’ll even put on the brakes if the drivers don’t.
M: Tell me, Cindy, will these cars be smart enough to fill themselves up with gas?
W: Not that I know of. Why do you ask?
M: Well, I’m late not because I got lost—I’m late because I ran out of gas on the way over here.