diff --git a/ch5/ch5-05.md b/ch5/ch5-05.md
index cb668f8..62c3ef8 100644
--- a/ch5/ch5-05.md
+++ b/ch5/ch5-05.md
@@ -119,6 +119,7 @@ $ ./outline2 http://gopl.io
 ```Go
 	func ElementByID(doc *html.Node, id string) *html.Node
 ```
+
 練習 **5.9** ：編寫函數 expand,將s中的"foo"替換爲f("foo")的返迴值。
 
 ```go