public class Test{public static void main(String args[]){Person stu = new Student();// 输入Person的时候,【ctrl+space】或【alt + /】就会弹出你所说的想象,这说明该类是抽象类。此外,抽象类是不能被实例化的。只有其子类可以。}}abstract class Person {public Person() {System.out.println("private constructor");}abstract public void pringString();}class Student exte...