diff --git a/en/assets/CNAME b/en/assets/CNAME
index c6cd02a..085168d 100644
--- a/en/assets/CNAME
+++ b/en/assets/CNAME
@@ -1 +1 @@
-practice.rs
\ No newline at end of file
+practice.course.rs
\ No newline at end of file
diff --git a/en/assets/lang.js b/en/assets/lang.js
deleted file mode 100644
index 061d375..0000000
--- a/en/assets/lang.js
+++ /dev/null
@@ -1,26 +0,0 @@
-(function () {
-    var path = window.location.pathname;
-    var link = "https://practice.rs" + path;
-    var word = "English";
-    var lang = "zh-CN";
-    var changeLang = "切换到英语";
-    
-    if (window.location.href.indexOf("zh.") == -1) {
-        link = "https://zh.practice.rs" + path;
-        word = "简体中文";
-        lang = "en";
-        changeLang = "Switch to Chinese"
-    }
-    
-    var lang_node = '';
-    if (link != '') {
-      lang_node = '<a href="' + link + '" title="' + changeLang + '" aria-label="' + changeLang + '"><i id="change-language-button" class="fa fa-language"> ' + word + '</i></a>';
-    }
-
-    console.log(lang_node)
-    var insertNode = document.getElementsByClassName('right-buttons');
-    if (insertNode.length > 0) {
-      var html = insertNode[0].innerHTML;
-      insertNode[0].innerHTML = html + lang_node;
-    }
-  })()  
\ No newline at end of file
diff --git a/en/assets/lang1.js b/en/assets/lang1.js
new file mode 100644
index 0000000..adf2b00
--- /dev/null
+++ b/en/assets/lang1.js
@@ -0,0 +1,35 @@
+(function () {
+  var path = window.location.pathname;
+  var link = "https://practice.course.rs" + path;
+  var word = "English";
+  var lang = "zh-CN";
+  var changeLang = "切换到英语";
+
+  if (window.location.href.indexOf("zh.") == -1) {
+    link = "https://practice-zh.course.rs" + path;
+    word = "简体中文";
+    lang = "en";
+    changeLang = "Switch to Chinese";
+  }
+
+  var lang_node = "";
+  if (link != "") {
+    lang_node =
+      '<a href="' +
+      link +
+      '" title="' +
+      changeLang +
+      '" aria-label="' +
+      changeLang +
+      '"><i id="change-language-button" class="fa fa-language"> ' +
+      word +
+      "</i></a>";
+  }
+
+  console.log(lang_node);
+  var insertNode = document.getElementsByClassName("right-buttons");
+  if (insertNode.length > 0) {
+    var html = insertNode[0].innerHTML;
+    insertNode[0].innerHTML = html + lang_node;
+  }
+})();
diff --git a/en/book.toml b/en/book.toml
index eae6c2c..abe5695 100644
--- a/en/book.toml
+++ b/en/book.toml
@@ -14,9 +14,9 @@ level = 1
 
 [output.html]
 additional-css = ["theme/style1.css"]
-additional-js = ["assets/custom3.js","assets/lang.js"]
+additional-js = ["assets/custom3.js", "assets/lang1.js"]
 git-repository-url = "https://github.com/sunface/rust-by-practice"
 edit-url-template = "https://github.com/sunface/rust-by-practice/edit/master/en/{path}"
 
 [rust]
-edition = "2021"
\ No newline at end of file
+edition = "2021"
diff --git a/zh-CN/assets/CNAME b/zh-CN/assets/CNAME
index ffc44bc..89e2aa2 100644
--- a/zh-CN/assets/CNAME
+++ b/zh-CN/assets/CNAME
@@ -1 +1 @@
-zh.practice.rs
\ No newline at end of file
+practice-zh.course.rs
\ No newline at end of file
diff --git a/zh-CN/assets/lang.js b/zh-CN/assets/lang.js
deleted file mode 100644
index 061d375..0000000
--- a/zh-CN/assets/lang.js
+++ /dev/null
@@ -1,26 +0,0 @@
-(function () {
-    var path = window.location.pathname;
-    var link = "https://practice.rs" + path;
-    var word = "English";
-    var lang = "zh-CN";
-    var changeLang = "切换到英语";
-    
-    if (window.location.href.indexOf("zh.") == -1) {
-        link = "https://zh.practice.rs" + path;
-        word = "简体中文";
-        lang = "en";
-        changeLang = "Switch to Chinese"
-    }
-    
-    var lang_node = '';
-    if (link != '') {
-      lang_node = '<a href="' + link + '" title="' + changeLang + '" aria-label="' + changeLang + '"><i id="change-language-button" class="fa fa-language"> ' + word + '</i></a>';
-    }
-
-    console.log(lang_node)
-    var insertNode = document.getElementsByClassName('right-buttons');
-    if (insertNode.length > 0) {
-      var html = insertNode[0].innerHTML;
-      insertNode[0].innerHTML = html + lang_node;
-    }
-  })()  
\ No newline at end of file
diff --git a/zh-CN/assets/lang1.js b/zh-CN/assets/lang1.js
new file mode 100644
index 0000000..1f6e8a3
--- /dev/null
+++ b/zh-CN/assets/lang1.js
@@ -0,0 +1,35 @@
+(function () {
+  var path = window.location.pathname;
+  var link = "https://practice.course.rs" + path;
+  var word = "English";
+  var lang = "zh-CN";
+  var changeLang = "切换到英语";
+
+  if (window.location.href.indexOf("zh.") == -1) {
+    link = "https://practice-zh.practice.rs" + path;
+    word = "简体中文";
+    lang = "en";
+    changeLang = "Switch to Chinese";
+  }
+
+  var lang_node = "";
+  if (link != "") {
+    lang_node =
+      '<a href="' +
+      link +
+      '" title="' +
+      changeLang +
+      '" aria-label="' +
+      changeLang +
+      '"><i id="change-language-button" class="fa fa-language"> ' +
+      word +
+      "</i></a>";
+  }
+
+  console.log(lang_node);
+  var insertNode = document.getElementsByClassName("right-buttons");
+  if (insertNode.length > 0) {
+    var html = insertNode[0].innerHTML;
+    insertNode[0].innerHTML = html + lang_node;
+  }
+})();
diff --git a/zh-CN/book.toml b/zh-CN/book.toml
index 9e3feb1..6ec0e15 100644
--- a/zh-CN/book.toml
+++ b/zh-CN/book.toml
@@ -14,9 +14,9 @@ level = 1
 
 [output.html]
 additional-css = ["theme/style1.css"]
-additional-js = ["assets/custom3.js","assets/lang.js"]
+additional-js = ["assets/custom3.js", "assets/lang1.js"]
 git-repository-url = "https://github.com/sunface/rust-by-practice"
 edit-url-template = "https://github.com/sunface/rust-by-practice/edit/master/zh-CN/{path}"
 
 [rust]
-edition = "2021"
\ No newline at end of file
+edition = "2021"
diff --git a/zh-CN/src/collections/hashmap.md b/zh-CN/src/collections/hashmap.md
index 296103c..a8523e7 100644
--- a/zh-CN/src/collections/hashmap.md
+++ b/zh-CN/src/collections/hashmap.md
@@ -149,7 +149,7 @@ fn main() {
 
 ### 容量
 
-关于容量，我们在之前的 [Vector](https://zh.practice.rs/collections/vector.html#容量) 中有详细的介绍，而 `HashMap` 也可以调整容量: 你可以通过 `HashMap::with_capacity(uint)` 使用指定的容量来初始化，或者使用 `HashMap::new()` ，后者会提供一个默认的初始化容量。
+关于容量，我们在之前的 [Vector](https://practice-zh.course.rs/collections/vector.html#容量) 中有详细的介绍，而 `HashMap` 也可以调整容量: 你可以通过 `HashMap::with_capacity(uint)` 使用指定的容量来初始化，或者使用 `HashMap::new()` ，后者会提供一个默认的初始化容量。
 
 #### 示例