diff --git a/Introduction.md b/Introduction.md
index e774c61..82ff6cc 100644
--- a/Introduction.md
+++ b/Introduction.md
@@ -90,12 +90,10 @@
 <ul>
 <li>图中的协议4byte header，主要是描述整个binlog网络包的length</li>
 <li>binlog event structure，详细信息请参考： 
-
 ~~http://forge.mysql.com/wiki/MySQL_Internals_Binary_Log~~
+
 <a href="https://dev.mysql.com/doc/internals/en/binary-log.html">https://dev.mysql.com/doc/internals/en/binary-log.html</a>
-
 <a href="https://dev.mysql.com/doc/internals/en/event-structure.html">https://dev.mysql.com/doc/internals/en/event-structure.html</a>
-
 <a href="https://dev.mysql.com/doc/internals/en/binlog-event.html">https://dev.mysql.com/doc/internals/en/binlog-event.html</a>
 
 </li>