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，时速80km/h ");
    }
}

class Bike extends Vehicle {
    @Override
    public void run() {
        System.out.println("自行车在非机动车道骑行，时速15km/h ");
    }
}

class Truck extends Vehicle {
    @Override
    public void run() {
        System.out.println("卡车在高速上运输货物，时速60km/h ");
    }
}

public class VehicleTest {
    public static void main(String[] args) {
        Vehicle[] vehicles = {
            new Car(),
            new Bike(),
            new Truck()
        };

        for (Vehicle v : vehicles) {
            v.run();
        }
    }
}