diff --git a/README.md b/README.md
index 3d7550a..728b86b 100644
--- a/README.md
+++ b/README.md
@@ -16,8 +16,7 @@
       <li><a href='https://github.com/ben1234560/AiLearning-Theory-Applying/blob/master/%E5%BF%85%E5%A4%87%E6%95%B0%E5%AD%A6%E5%9F%BA%E7%A1%80.md#%E7%9F%A9%E9%98%B5%E5%92%8C%E7%89%B9%E5%BE%81'>矩阵和特征</a>
       <li><a href='https://github.com/ben1234560/AiLearning-Theory-Applying/blob/master/%E5%BF%85%E5%A4%87%E6%95%B0%E5%AD%A6%E5%9F%BA%E7%A1%80.md#svd%E7%9F%A9%E9%98%B5%E5%88%86%E8%A7%A3'>SVD矩阵分解</a>
       <li><a href='https://github.com/ben1234560/AiLearning-Theory-Applying/blob/master/%E5%BF%85%E5%A4%87%E6%95%B0%E5%AD%A6%E5%9F%BA%E7%A1%80.md#%E7%A6%BB%E6%95%A3%E5%92%8C%E8%BF%9E%E7%BB%AD%E5%9E%8B%E6%95%B0%E6%8D%AE'>离散和连续型数据</a>
-      <li><a href='https://github.com/ben1234560/AiLearning-Theory-Applying/blob/master/%E5%BF%85%E5%A4%87%E6%95%B0%E5%AD%A6%E5%9F%BA%E7%A1%80.md#%E7%AE%80%E5%8D%95%E9%9A%8F%E6%9C%BA%E6%8A%BD%E6%A0%B7'>XXX</a>
-      <li><a href=''>简单随机抽样</a>
+      <li><a href='https://github.com/ben1234560/AiLearning-Theory-Applying/blob/master/%E5%BF%85%E5%A4%87%E6%95%B0%E5%AD%A6%E5%9F%BA%E7%A1%80.md#%E7%AE%80%E5%8D%95%E9%9A%8F%E6%9C%BA%E6%8A%BD%E6%A0%B7'>简单随机抽样</a>
       <li><a href='https://github.com/ben1234560/AiLearning-Theory-Applying/blob/master/%E5%BF%85%E5%A4%87%E6%95%B0%E5%AD%A6%E5%9F%BA%E7%A1%80.md#%E6%9E%81%E5%A4%A7%E4%BC%BC%E7%84%B6%E4%BC%B0%E8%AE%A1'>极大似然估计</a>
     </ul>
   </li>
@@ -29,3 +28,4 @@
 </ul>
 
 
+