diff --git a/source/_posts/downloads.md b/source/_posts/downloads.md
index 60f7e8f..38ea688 100644
--- a/source/_posts/downloads.md
+++ b/source/_posts/downloads.md
@@ -41,6 +41,8 @@ tags:
 
 [第二次上机讲解.pptx](/~zhaozuohong/resources/Experiment2.pptx)
 
+[第三次上机讲解.pptx](/~zhaozuohong/resources/Experiment3.pptx)
+
 # 其它参考资料
 
 [C语言程序设计习题选编.pdf](/~zhaozuohong/resources/C-experiments.ppt)