diff --git a/help/_posts/1970-01-01-chef.md b/help/_posts/1970-01-01-chef.md
index 7d96be5..468db79 100644
--- a/help/_posts/1970-01-01-chef.md
+++ b/help/_posts/1970-01-01-chef.md
@@ -18,10 +18,11 @@ Chef 是一套自动化运维工具。
 	<select class="form-control release-select" data-template="#apt-template" data-target="#apt-content">
 		<option data-os="debian" data-release="jessie">Debian 8 (Jessie)</option>
 		<option data-os="debian" data-release="stretch">Debian 9 (Stretch)</option>
-		<option data-os="debian" data-release="buster" selected>Debian 10 (Buster)</option>
-		<option data-os="ubuntu" data-release="trusty">Ubuntu 14.04 LTS</option>
+		<option data-os="debian" data-release="buster">Debian 10 (Buster)</option>
+		<option data-os="debian" data-release="bullseye" selected>Debian 11 (Bullseye)</option>
 		<option data-os="ubuntu" data-release="xenial">Ubuntu 16.04 LTS</option>
 		<option data-os="ubuntu" data-release="bionic">Ubuntu 18.04 LTS</option>		
+		<option data-os="ubuntu" data-release="focal">Ubuntu 20.04 LTS</option>
 </select>
 </div>
 </form>