abstract class Vehicle {
    public abstract void  run();
}
class Car extends Vehicle {
    @Override
    public void run() {
        System.out.println("汽车在公路上行驶");
    }
}
class Bike extends Vehicle {
    @Override
    public void run() {
        System.out.println("自行车在非机动车道行驶");
    }
}
class Truck extends Vehicle {
    @Override
    public void run() {
        System.out.println("卡车在货运道路行驶");
    }
}
public class VehicleTest {
    public static  void main (String[] args) {
        Vehicle[] vehicles = {new Car(),new Bike(),new Truck()};
        for (Vehicle v : vehicles) {
            v.run();
        }
    }
}