diff --git a/game_functions.py b/game_functions.py
deleted file mode 100644
index de8679d..0000000
--- a/game_functions.py
+++ /dev/null
@@ -1,69 +0,0 @@
-import sys
-
-import pygame
-
-from bullet import Bullet
-
-
-def check_keydown_events(event, ai_settings, screen, ship, bullets):
-   # 移动飞船
-   if event.key == pygame.K_RIGHT:
-       ship.moving_right = True
-   elif event.key == pygame.K_LEFT:
-       ship.moving_left = True
-   elif event.key == pygame.K_SPACE:
-       fire_bullet(ai_settings, screen, ship, bullets)
-
-
-def check_keyup_events(event, ship):
-   # 停止移动飞船
-   if event.key == pygame.K_RIGHT:
-       ship.moving_right = False
-   elif event.key == pygame.K_LEFT:
-       ship.moving_left = False
-
-
-def check_events(ai_settings, screen, ship, bullets):
-   """响应按键和鼠标事件"""
-   for event in pygame.event.get():
-       if event.type == pygame.QUIT:
-           sys.exit()
-
-       elif event.type == pygame.KEYDOWN:
-           check_keydown_events(event, ai_settings, screen, ship, bullets)
-
-       elif event.type == pygame.KEYUP:
-           check_keyup_events(event, ship)
-
-
-def fire_bullet(ai_settings, screen, ship, bullets):
-   """如果还没有达到限制，就发射一颗子弹"""
-   if len(bullets) < ai_settings.bullets_allowed:
-       # 创建一个子弹，并将其加入编组bullets
-       new_bullet = Bullet(ai_settings, screen, ship)
-       bullets.add(new_bullet)
-
-
-def update_screen(ai_settings, screen, ship, bullets):
-   """更新屏幕上的图像，并切换到新屏幕"""
-   # 用背景色填充屏幕
-   screen.fill(ai_settings.bg_color)
-   # 在飞船和外星人后面重新绘制所有的子弹
-   for bullet in bullets.sprites():
-       bullet.draw_bullet()
-
-   # 绘制飞船图形
-   ship.blitme()
-
-   # 让最近绘制的屏幕可见(刷新屏幕)
-   pygame.display.flip()
-
-
-def update_bullets(bullets):
-   """更新子弹位置，并删除已经消失的子弹"""
-   bullets.update()
-
-   # 删除子弹
-   for bullet in bullets.copy():
-       if bullet.rect.bottom <= 0:
-           bullets.remove(bullet)
\ No newline at end of file