diff --git a/w6/Animal.java b/w6/Animal.java
new file mode 100644
index 0000000..9cb24d2
--- /dev/null
+++ b/w6/Animal.java
@@ -0,0 +1,6 @@
+package w6;
+
+public abstract class Animal {
+    // 抽象方法：声明动物“叫”的行为，不写具体实现
+    public abstract void makeSound();
+}
\ No newline at end of file
diff --git a/w6/Cat.java b/w6/Cat.java
new file mode 100644
index 0000000..ffa16b5
--- /dev/null
+++ b/w6/Cat.java
@@ -0,0 +1,9 @@
+package w6;
+
+public class Cat extends Animal {
+    // 重写Animal的抽象方法makeSound()
+    @Override
+    public void makeSound() {
+        System.out.println("喵喵");
+    }
+}
\ No newline at end of file
diff --git a/w6/Dog.java b/w6/Dog.java
new file mode 100644
index 0000000..ac8d198
--- /dev/null
+++ b/w6/Dog.java
@@ -0,0 +1,16 @@
+package w6;
+
+public class Dog extends Animal
+        implements Swimmable {
+    // 重写Animal的抽象方法makeSound()
+    @Override
+    public void makeSound() {
+        System.out.println("汪汪");
+    }
+
+    // 步骤3实现Swimmable接口后，需重写swim()方法
+    @Override
+    public void swim() {
+        System.out.println("狗会游泳～");
+    }
+}
diff --git a/w6/Main.java b/w6/Main.java
new file mode 100644
index 0000000..ed2929c
--- /dev/null
+++ b/w6/Main.java
@@ -0,0 +1,17 @@
+package w6;
+
+public class Main {
+    public static void main(String[] args) {
+        // 测试1：Animal 引用指向 Dog（多态调用makeSound()）
+        Animal animalDog = new Dog();
+        animalDog.makeSound(); // 输出：汪汪（实际执行Dog的makeSound()）
+
+        // 测试2：Swimmable 引用指向 Dog（多态调用swim()）
+        Swimmable swimmingDog = new Dog();
+        swimmingDog.swim(); // 输出：狗会游泳～（实际执行Dog的swim()）
+
+        // 测试3：Animal 引用指向 Cat（多态调用makeSound()）
+        Animal animalCat = new Cat();
+        animalCat.makeSound(); // 输出：喵喵（实际执行Cat的makeSound()）
+    }
+}
diff --git a/w6/Swimmable.java b/w6/Swimmable.java
new file mode 100644
index 0000000..3ca3075
--- /dev/null
+++ b/w6/Swimmable.java
@@ -0,0 +1,5 @@
+package w6;
+
+public interface Swimmable {
+    void swim();
+}