diff --git a/W3/Car.class b/W3/Car.class
new file mode 100644
index 0000000..bc990ff
Binary files /dev/null and b/W3/Car.class differ
diff --git a/W3/Car.java b/W3/Car.java
new file mode 100644
index 0000000..86c960f
--- /dev/null
+++ b/W3/Car.java
@@ -0,0 +1,77 @@
+package com.rental;
+public class Car {
+    private String licensePlate;
+    private String brand;
+    private String model;
+    private double dailyRent;
+    private boolean isRented;
+    private static int totalCars = 0;
+    public Car(String licensePlate, String brand, String model, double dailyRent) {
+        this.licensePlate = licensePlate;
+        this.brand = brand;
+        this.model = model;
+        this.dailyRent = dailyRent;
+        this.isRented = false;
+        totalCars++;
+    }
+    public Car(String licensePlate, String brand, String model) {
+        this(licensePlate, brand, model, 300.0);
+    }
+    public String getLicensePlate() {
+        return licensePlate;
+    }
+    public String getBrand() {
+        return brand;
+    }
+    public void setBrand(String brand) {
+        this.brand = brand;
+    }
+    public String getModel() {
+        return model;
+    }
+    public void setModel(String model) {
+        this.model = model;
+    }
+    public double getDailyRent() {
+        return dailyRent;
+    }
+    public void setDailyRent(double dailyRent) {
+        if (dailyRent > 0) {
+            this.dailyRent = dailyRent;
+        } else {
+            System.out.println("Daily rent must be greater than 0, modification failed");
+        }
+    }
+    public boolean isRented() {
+        return isRented;
+    }
+    public void rentCar() {
+        if (isRented) {
+            System.out.println("The car is already rented and cannot be rented again");
+        } else {
+            isRented = true;
+            System.out.println("Car rented successfully");
+        }
+    }
+    public void returnCar() {
+        if (!isRented) {
+            System.out.println("The car is not rented, no need to return");
+        } else {
+            isRented = false;
+            System.out.println("Car returned successfully");
+        }
+    }
+    public double calculateRent(int days) {
+        return dailyRent * days;
+    }
+    public static int getTotalCars() {
+        return totalCars;
+    }
+    public void displayInfo() {
+        System.out.println("License Plate: " + licensePlate
+                + ", Brand: " + brand
+                + ", Model: " + model
+                + ", Daily Rent: " + dailyRent
+                + ", Status: " + (isRented ? "Rented" : "Available"));
+    }
+}
\ No newline at end of file
diff --git a/W3/TestCar.class b/W3/TestCar.class
new file mode 100644
index 0000000..54492ef
Binary files /dev/null and b/W3/TestCar.class differ
diff --git a/W3/TestCar.java b/W3/TestCar.java
new file mode 100644
index 0000000..553249c
--- /dev/null
+++ b/W3/TestCar.java
@@ -0,0 +1,25 @@
+package com.rental;
+public class TestCar {
+    public static void main(String[] args) {
+        Car car1 = new Car("XiangA12345", "BYD", "Han EV", 280.0);
+        Car car2 = new Car("XiangB67890", "Tesla", "Model 3");
+        Car car3 = new Car("XiangC00001", "Toyota", "Camry", 350.0);
+        System.out.println("=== Initial Car Information ===");
+        car1.displayInfo();
+        car2.displayInfo();
+        car3.displayInfo();
+        System.out.println("\n=== Test Rent/Return ===");
+        car1.rentCar();
+        car1.rentCar();
+        car1.returnCar();
+        car1.returnCar();
+        System.out.println("\n=== Calculate Rent ===");
+        double total = car2.calculateRent(5);
+        System.out.println("car2 5-day rent: " + total);
+        System.out.println("\n=== Test Invalid Rent ===");
+        car3.setDailyRent(-100);
+        System.out.println("car3 rent: " + car3.getDailyRent());
+        System.out.println("\n=== Total Cars ===");
+        System.out.println("Total: " + Car.getTotalCars());
+    }
+}
\ No newline at end of file
diff --git a/W3/实验报告.doc b/W3/实验报告.doc
new file mode 100644
index 0000000..77a41ed
Binary files /dev/null and b/W3/实验报告.doc differ