diff --git a/_includes/foot.html b/_includes/foot.html
index 5255727..34c6c2b 100644
--- a/_includes/foot.html
+++ b/_includes/foot.html
@@ -3,11 +3,15 @@
     <nav class="translation-nav">
         <span>Translations:</span>
         <a href="{{ site.url }}" itemprop="availableLanguage" itemscope itemtype="http://schema.org/Language">
-            <span itemprop="name" alternateName="en">English</span>
+            <span itemprop="name" alternateName="en" title="English">English</span>
         </a>
         ·
         <a href="{{ site.url }}/jp" itemprop="availableLanguage" itemscope itemtype="http://schema.org/Language">
-            <span itemprop="name" alternateName="ja">日本語</span>
+            <span itemprop="name" alternateName="ja" title="Japanese">日本語</span>
+        </a>
+        ·
+        <a href="{{ site.url }}/zh" itemprop="availableLanguage" itemscope itemtype="http://schema.org/Language">
+            <span itemprop="name" alternateName="zh" title="Simplified Chinese">简体中文</span>
         </a>
     </nav>
     <p>
diff --git a/_includes/head.html b/_includes/head.html
index ba46554..ce5c635 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -5,11 +5,15 @@
     <div class="wrap">
         <nav class="translation-nav">
             <a href="{{ site.url }}" itemprop="availableLanguage" itemscope itemtype="http://schema.org/Language">
-                <span itemprop="name" alternateName="en">English</span>
+                <span itemprop="name" alternateName="en" title="English">English</span>
             </a>
             ·
             <a href="{{ site.url }}/jp" itemprop="availableLanguage" itemscope itemtype="http://schema.org/Language">
-                <span itemprop="name" alternateName="ja">日本語</span>
+                <span itemprop="name" alternateName="ja" title="Japanese">日本語</span>
+            </a>
+            ·
+            <a href="{{ site.url }}/zh" itemprop="availableLanguage" itemscope itemtype="http://schema.org/Language">
+                <span itemprop="name" alternateName="zh" title="Simplified Chinese">简体中文</span>
             </a>
         </nav>
     </div>
diff --git a/_includes/sqlstyle.guide.zh.md b/_includes/sqlstyle.guide.zh.md
index 9923d28..f74b3f0 100644
--- a/_includes/sqlstyle.guide.zh.md
+++ b/_includes/sqlstyle.guide.zh.md
@@ -141,11 +141,23 @@ SELECT model_num
 用空格使根关键字都结束在同一列上。在代码中形成一个从上到下的“川流”，这样帮助读者快速扫描代码并将关键字和实现细节分开。川流在排版时应该避免，但是对书写SQL语句是有帮助的。
 
 ```sql
-SELECT f.average_height, f.average_diameter
-  FROM flora AS f
- WHERE f.species_name = 'Banksia'
-    OR f.species_name = 'Sheoak'
-    OR f.species_name = 'Wattle';
+(SELECT f.species_name,
+        AVG(f.height) AS average_height, AVG(f.diameter) AS average_diameter
+   FROM flora AS f
+  WHERE f.species_name = 'Banksia'
+     OR f.species_name = 'Sheoak'
+     OR f.species_name = 'Wattle'
+  GROUP BY f.species_name, f.observation_date)
+
+  UNION ALL
+
+(SELECT b.species_name,
+        AVG(b.height) AS average_height, AVG(b.diameter) AS average_diameter
+   FROM botanic_garden_flora AS b
+  WHERE b.species_name = 'Banksia'
+     OR b.species_name = 'Sheoak'
+     OR b.species_name = 'Wattle'
+  GROUP BY b.species_name, b.observation_date)
 ```
 
 注意`WHERE`和`FROM`等关键字，都右对齐，而真实的列名都左对齐。
@@ -1186,6 +1198,6 @@ ZONE
     "Wikipedia: Entity–attribute–value model"
 [self]: http://www.sqlstyle.guide
     "SQL style guide by Simon Holywell"
-[licence]: http://creativecommons.org/licenses/by-sa/4.0/
-    "Creative Commons Attribution-ShareAlike 4.0 International License"
+[licence-zh]: https://creativecommons.org/licenses/by-sa/4.0/deed.zh
+    "署名-相同方式共享 4.0 国际"
 </div>