下面代码中v1和v2调用了相同接口 move()，但输出结果不同，这体现了面向对象编程的（ ）特性。

class Vehicle:
    def __init__(self, brand):
        self._brand = brand # 私有属性用下划线表示

    def set_brand(self, brand):
        self._brand = brand

    def get_brand(self):
        return self._brand

    def move(self):
        print(f"{self._brand} is moving...")

class Car(Vehicle):
    def __init__(self, brand, seat_count):
        super().__init__(brand)
        self._seat_count = seat_count

    def show_info(self):
        print(f"This car is a {self.get_brand()} with {self._seat_count} seats.")

    def move(self):
        print(f"{self.get_brand()} car is driving on the road!")

class Bike(Vehicle):
    def __init__(self, brand):
        super().__init__(brand)

    def move(self):
        print(f"{self.get_brand()} bike is cycling on the path!")

def main():
    v1 = Car("Toyota", 5)
    v2 = Bike("Giant")

    v1.move() # 输出: Toyota car is driving on the road!
    v2.move() # 输出: Giant bike is cycling on the path!

if __name__ == "__main__":
    main()