给定控制台应用程序的输出是什么？(     )

public class Test28 { 
    public static void main(String[] args) { 
        Doc.test(); 
    } 
} 
class Doc { 
    public String summary() { 
        return "doc#"; 
    } 
    public static void test() { 
        Doc[] docs = new Doc[] {new Doc(), new Spec()}; 
        for (Doc d: docs) 
            System.out.print(d.summary()); 
    } 
} 
class Spec extends Doc { 
    public String summary() { 
        return "spc#"; 
    } 
}