Resposta - Exercício 4

Classe Animal:
``
namespace exercise72.Models;

internal class Animal
{
public virtual string EmitSound()
{
return "Animal sounds...";
}
}
``
Classe Mammal:

namespace exercise72.Models;

internal class Mammal : Animal
{
    public override string EmitSound()
    {
        return "Mammal sounds...";
    }
}

Classe Bird:

namespace exercise72.Models;

internal class Bird : Animal
{
    public override string EmitSound()
    {
        return "Bird sounds...";
    }
}

Classe Fish:

namespace exercise72.Models;

internal class Fish : Animal
{
    public override string EmitSound()
    {
        return "Fish sounds...";
    }
}

Instâncias:

using exercise72.Models;

Mammal mamal = new Mammal();
Console.WriteLine(mamal.EmitSound());

Bird bird = new Bird();
Console.WriteLine(bird.EmitSound());

Fish fish = new Fish();
Console.WriteLine(fish.EmitSound());