问为什么C＃不允许静态方法来实现一个接口？

// These items will be displayed in a list on the screen.

public interface IListItem {

  string ScreenName();

  ...

}

public class Animal: IListItem {

    // All animals will be called "Animal".

    public static string ScreenName() {

        return "Animal";

    }

....

}

public class Person: IListItem {

    private string name;

    // All persons will be called by their individual names.

    public string ScreenName() {

        return name;

    }

    ....

 }