diff --git a/w5/PolymorphismTest.class b/w5/PolymorphismTest.class
new file mode 100644
index 0000000..baaa4c5
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diff --git a/w5/PolymorphismTest.java b/w5/PolymorphismTest.java
new file mode 100644
index 0000000..3efbbe9
--- /dev/null
+++ b/w5/PolymorphismTest.java
@@ -0,0 +1,76 @@
+abstract class Person {
+    protected String name;
+    protected int age;
+
+    public Person(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public abstract void display();
+}
+
+class Student extends Person {
+    int studentId;
+    String major;
+
+    public Student(String name, int age, int studentId, String major) {
+        super(name, age);
+        this.studentId = studentId;
+        this.major = major;
+    }
+
+    @Override
+    public void display() {
+        System.out.println("学生信息 - 姓名:" + name + ", 年龄:" + age +
+                         ", 学号:" + studentId + ", 专业:" + major);
+    }
+}
+
+class Teacher extends Person {
+    String subject;
+    double salary;
+
+    public Teacher(String name, int age, String subject, double salary) {
+        super(name, age);
+        this.subject = subject;
+        this.salary = salary;
+    }
+
+    @Override
+    public void display() {
+        System.out.println("教师信息 - 姓名:" + name + ", 年龄:" + age +
+                         ", 科目:" + subject + ", 薪资:" + salary);
+    }
+}
+
+public class PolymorphismTest {
+    public static void addPerson(Person[] array, int count, Person p) {
+        if (count < array.length) {
+            array[count] = p;
+        }
+    }
+
+    public static void main(String[] args) {
+        Person[] persons = new Person[10];
+        int count = 0;
+
+        System.out.println("=== 挑战题测试 ===");
+
+        persons[count++] = new Student("张三", 20, 1001, "计算机科学");
+        persons[count++] = new Student("李四", 22, 1002, "软件工程");
+        persons[count++] = new Teacher("王老师", 35, "数据结构", 8000);
+        persons[count++] = new Teacher("刘老师", 40, "算法分析", 9000);
+
+        System.out.println("添加成功！共添加 " + count + " 人\n");
+
+        System.out.println("=== 所有人员信息 ===");
+        for (int i = 0; i < count; i++) {
+            persons[i].display();
+        }
+
+        System.out.println("\n=== 思考题解答 ===");
+        System.out.println("多态优势：addPerson(Person p) 统一处理不同类型");
+        System.out.println("添加特定属性问题：使用 instanceof 判断类型后强制转换");
+    }
+}
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diff --git a/w5/ShapeTest.class b/w5/ShapeTest.class
new file mode 100644
index 0000000..512084b
Binary files /dev/null and b/w5/ShapeTest.class differ
diff --git a/w5/ShapeTest.java b/w5/ShapeTest.java
new file mode 100644
index 0000000..e22cd4f
--- /dev/null
+++ b/w5/ShapeTest.java
@@ -0,0 +1,40 @@
+class Shape {
+    public void draw() {
+        System.out.println("绘制一个图形");
+    }
+}
+
+class Circle extends Shape {
+    @Override
+    public void draw() {
+        System.out.println("绘制一个圆形 ○");
+    }
+}
+
+class Rectangle extends Shape {
+    @Override
+    public void draw() {
+        System.out.println("绘制一个矩形 □");
+    }
+}
+
+public class ShapeTest {
+    public static void drawShape(Shape s) {
+        s.draw();
+    }
+
+    public static void main(String[] args) {
+        Circle circle = new Circle();
+        Rectangle rectangle = new Rectangle();
+
+        System.out.println("=== 基础题测试 ===");
+        drawShape(circle);
+        drawShape(rectangle);
+
+        Shape[] shapes = {new Circle(), new Rectangle(), new Shape()};
+        System.out.println("\n遍历数组：");
+        for (Shape s : shapes) {
+            drawShape(s);
+        }
+    }
+}
\ No newline at end of file
diff --git a/w5/VehicleTest.java b/w5/VehicleTest.java
new file mode 100644
index 0000000..f2c9360
--- /dev/null
+++ b/w5/VehicleTest.java
@@ -0,0 +1,37 @@
+abstract class Vehicle {
+    public abstract void run();
+}
+
+class Car extends Vehicle {
+    @Override
+    public void run() {
+        System.out.println("汽车在公路上行驶 🚗");
+    }
+}
+
+class Bike extends Vehicle {
+    @Override
+    public void run() {
+        System.out.println("自行车在自行车道骑行 🚲");
+    }
+}
+
+class Truck extends Vehicle {
+    @Override
+    public void run() {
+        System.out.println("卡车在高速公路行驶 🚛");
+    }
+}
+
+public class VehicleTest {
+    public static void main(String[] args) {
+        Vehicle[] vehicles = {new Car(), new Bike(), new Truck()};
+
+        System.out.println("=== 进阶题测试 ===");
+        System.out.println("车辆运行情况：");
+        for (int i = 0; i < vehicles.length; i++) {
+            System.out.print((i + 1) + ". ");
+            vehicles[i].run();
+        }
+    }
+}
\ No newline at end of file