interface ISkill
{
　　void Flying();
}

//隐式实现ISkill接口
public class Bird: ISkill
{
　　public void Flying()
    {            
    }
}

1 //第一种调用方式
2 Bird bird = new Bird();
3 bird.Flying();
4 
5 //第二种调用方式
6  ISkill secondBrid = new Bird();
7  secondBrid.Flying();

interface ISkill
{
     void Flying();
}

public class Bird : ISkill
{
       //方法名称为接口名.方法名
      void ISkill.Flying()
      {          
      }
}

ISkill secondBrid = new Bird();
secondBrid.Flying();

Bird bird = new Bird();
bird.Flying();