diff --git a/w6/AnimalSystem.java b/w6/AnimalSystem.java
new file mode 100644
index 0000000..28feaa6
--- /dev/null
+++ b/w6/AnimalSystem.java
@@ -0,0 +1,46 @@
+package java01;
+abstract class Animal {
+    public abstract void makeSound();
+}
+interface Swimmable {
+    void swim();
+}
+class Dog extends Animal implements Swimmable {
+    @Override
+    public void makeSound() {
+        System.out.println("狗：汪汪汪");
+    }
+
+    @Override
+    public void swim() {
+        System.out.println("狗会游泳");
+    }
+}
+class Cat extends Animal {
+    @Override
+    public void makeSound() {
+        System.out.println("猫：喵喵喵");
+    }
+}
+
+public class AnimalSystem {
+    public static void main(String[] args) {
+        Animal animal1 = new Dog();
+        Animal animal2 = new Cat();
+        animal1.makeSound();
+        animal2.makeSound();
+
+        System.out.println("----------");
+        if (animal1 instanceof Swimmable) {
+            Swimmable swimmer = (Swimmable) animal1;
+            swimmer.swim();
+        }
+
+        if (animal2 instanceof Swimmable) {
+            Swimmable swimmer = (Swimmable) animal2;
+            swimmer.swim();
+        } else {
+            System.out.println("猫不会游泳");
+        }
+    }
+}
\ No newline at end of file
diff --git a/w6/运行截图.png b/w6/运行截图.png
new file mode 100644
index 0000000..c058c1a
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