diff --git a/docs/坦克大战笔记.docx b/docs/坦克大战笔记.docx
index 666b8f0..fb28f85 100644
Binary files a/docs/坦克大战笔记.docx and b/docs/坦克大战笔记.docx differ
diff --git a/src/com/demo/tank/coruse2/Bullet.java b/src/com/demo/tank/coruse2/Bullet.java
index d43266e..804d89c 100644
--- a/src/com/demo/tank/coruse2/Bullet.java
+++ b/src/com/demo/tank/coruse2/Bullet.java
@@ -8,14 +8,20 @@ public class Bullet {
     private static final int SPEED = 5;
     private static final int WIDTH = 20;
     private static final int HEIGHT = 20;
+    private boolean live = true;
+    private TankFrame tf;
 
-    public Bullet(int x, int y, Direction direction) {
+    public Bullet(int x, int y, Direction direction, TankFrame tf) {
         this.x = x;
         this.y = y;
         this.direction = direction;
+        this.tf = tf;
     }
 
     public void paint(Graphics g){
+        if(!live){
+            tf.bullets.remove(this);
+        }
         Color color = g.getColor();
         g.setColor(Color.RED);
         g.fillOval(x, y, WIDTH, HEIGHT);
@@ -36,6 +42,9 @@ public class Bullet {
             default:
                 break;
         }
+        if(x < 0 || y<0 || x> TankFrame.GAME_WIDTH || x > TankFrame.GAME_HEIGHT){
+            live = false;
+        }
     }
 
 
@@ -62,4 +71,12 @@ public class Bullet {
     public void setDirection(Direction direction) {
         this.direction = direction;
     }
+
+    public boolean isLive() {
+        return live;
+    }
+
+    public void setLive(boolean live) {
+        this.live = live;
+    }
 }
diff --git a/src/com/demo/tank/coruse2/Tank.java b/src/com/demo/tank/coruse2/Tank.java
index 5615af9..6291594 100644
--- a/src/com/demo/tank/coruse2/Tank.java
+++ b/src/com/demo/tank/coruse2/Tank.java
@@ -74,7 +74,6 @@ public class Tank {
     }
 
     public void fire() {
-        Bullet bullet = new Bullet(x+15, y, this.dir);
-        tankFrame.bullet = bullet;
+        tankFrame.bullets.add(new Bullet(x, y, this.dir, tankFrame));
     }
 }
diff --git a/src/com/demo/tank/coruse2/TankFrame.java b/src/com/demo/tank/coruse2/TankFrame.java
index be41f05..0caff8f 100644
--- a/src/com/demo/tank/coruse2/TankFrame.java
+++ b/src/com/demo/tank/coruse2/TankFrame.java
@@ -5,14 +5,18 @@ import java.awt.event.KeyAdapter;
 import java.awt.event.KeyEvent;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
 
 public class TankFrame extends Frame {
-    private static final int GAME_WIDTH = 800;
-    private static final int GAME_HEIGHT = 600;
+    public static final int GAME_WIDTH = 800;
+    public static final int GAME_HEIGHT = 600;
     Image image = null;
 
     Tank tank = new Tank(500, 500, Direction.UP, this);
-    Bullet bullet = new Bullet(520, 440, Direction.UP);
+//    Bullet bullet = new Bullet(520, 440, Direction.UP);
+    List<Bullet> bullets = new ArrayList();
 
     public TankFrame(){
         setVisible(true);
@@ -44,8 +48,26 @@ public class TankFrame extends Frame {
 
     @Override
     public void paint(Graphics g){
+        //打印出子弹数量
+        Color color = g.getColor();
+        g.setColor(Color.WHITE);
+        g.drawString("当前子弹数量:" + bullets.size(), 60, 50);
+        g.setColor(color);
+
         tank.paint(g);
-        bullet.paint(g);
+        for (int i = 0; i< bullets.size(); i++){
+            bullets.get(i).paint(g);
+        }
+//        for(Iterator<Bullet> it = bullets.iterator(); it.hasNext();){
+//            Bullet b = it.next();
+//            if(!b.isLive()){
+//                it.remove();
+//            }
+//        }
+//
+//        for (Bullet b : bullets){
+//            b.paint(g);
+//        }
     }
 
     class MyKeyListener extends KeyAdapter{