diff --git a/problems/0704.二分查找.md b/problems/0704.二分查找.md
index 635868a9..15e096a0 100644
--- a/problems/0704.二分查找.md
+++ b/problems/0704.二分查找.md
@@ -561,7 +561,7 @@ class Solution {
 }
 ```
 
-**C#**
+**C#:**
 ```csharp
 //左闭右闭
 public class Solution {