diff --git a/snake.py b/snake.py
index 537316e..721d7e4 100644
--- a/snake.py
+++ b/snake.py
@@ -1,68 +1,64 @@
 import pygame
 from pygame import locals
-
-# 初始化pygame,为使用硬件做准备
+from random import *
+# 初始化pygame,为使用pygame做准备
 pygame.init()
 
 # 创建一个窗口
-screen = pygame.display.set_mode((660, 480))
-FPSCLOCK = pygame.time.Clock()  # pygame时钟,控制游戏速度(帧数)
-
-# 背景
-background = pygame.image.load('bg.png')
-right = pygame.image.load('right.png')      # 头 朝右
-food = pygame.image.load('apple.png')       # 食物 苹果
-body = pygame.image.load('body.png')        # 身体
-left = pygame.image.load('left.png')        # 头 朝左
-up = pygame.image.load('up.png')            # 头 朝上
-down = pygame.image.load('down.png')        # 头 朝下
-
-x, y = 240, 120
-position = [(180, 90), (180, 120), (210, 120), (x, y)]
-
+screen = pygame.display.set_mode((660,480))
+bg = pygame.image.load("bg.png")
+right = pygame.image.load("right.png")
+left = pygame.image.load("left.png")
+up = pygame.image.load("up.png")
+down = pygame.image.load("down.png")
+food = pygame.image.load("apple.png")
+body = pygame.image.load("body.png")
+FPS = pygame.time.Clock()
+x,y = 240,120
+position = [(180,90),(180,120),(210,120),(x,y)]
 setheading = "right"
-snake_head = right
-
+snake_heading = right
+a_x = 360
+a_y = 300
 while True:
     for event in pygame.event.get():
         if event.type == locals.QUIT:
-            # 接收到退出事件后退出程序
             exit()
-        if event.type == locals.KEYDOWN:
-            if event.key == locals.K_RIGHT and setheading != "left":
+        elif event.type == locals.KEYDOWN:
+            if event.key == locals.K_RIGHT and setheading != 'left':
                 setheading = 'right'
-                snake_head = right
-            if event.key == locals.K_LEFT and setheading != "right":
+                snake_heading = right
+            elif event.key == locals.K_LEFT and setheading != 'right':
                 setheading = 'left'
-                snake_head = left
-            if event.key == locals.K_UP and setheading != "down":
+                snake_heading = left
+            elif event.key == locals.K_UP and setheading != 'down':
                 setheading = 'up'
-                snake_head = up
-            if event.key == locals.K_DOWN and setheading != "up":
+                snake_heading = up
+            else:
                 setheading = 'down'
-                snake_head = down
-
-    # 设置贪吃蛇的头部坐标
-    if setheading == "right":
+                snake_heading = down
+    
+    if setheading == 'right':
         x += 30
-    elif setheading == "left":
+    elif setheading == 'left':
         x -= 30
-    elif setheading == "up":
+    elif setheading == 'up':
         y -= 30
     else:
         y += 30
-    position.append((x, y))
+    
+    position.append((x,y))
+    last = position[0]
     position.pop(0)
-    # 将背景图画上去
-    screen.blit(background, (0, 0))
-    # 将贪吃蛇的头画上去
-    screen.blit(snake_head, position[-1])
-    # 将贪吃蛇的身体画上去
-    for i in range(len(position)-1):
-        screen.blit(body, position[i])
+    screen.blit(bg,(0,0))
 
-    # 将果实画上去
-    screen.blit(food, (360, 300))
-    # 刷新画面
+    screen.blit(snake_heading,position[-1])
+    for i in range(len(position)-1):
+        screen.blit(body,position[i])
+    
+    if x == a_x and y == a_y:
+        a_x = randint(0,21)*30
+        a_y = randint(0,15)*30
+    screen.blit(food,(a_x,a_y))
     pygame.display.update()
-    FPSCLOCK.tick(3)
\ No newline at end of file
+    FPS.tick(3)
\ No newline at end of file