①In Tianjin, some people are at the bus stop. Soon, a bus comes. It is different from the usual buses on the street. It looks like a panda.
②After getting on the bus, people only need to buy their tickets (票) by scanning (扫描) their hands! About one minute later, the bus starts its self-driving. It stops for traffic lights (交通信号灯) automatically (自动地) before it gets to the next stop. That's to say, it can drive and stop with no help. But there is still a driver on the bus. He will do something if the bus is in danger.
③There are also some robots on the bus. People can talk to them and ask them for help. If there is a bad man on the bus, the robots will call the police. "It's easy, " says a woman taking the bus. "And children love the bus because there are many pictures of pandas on it. "
④This kind of bus is working in ten cities all over China. More cities in China will have this kind of bus this year. I think soon you can take the bus in your city.
a. Call the police. b. Talk to people. c. Play with children. d. Drive the bus.