diff --git a/njuthesis.dtx b/njuthesis.dtx
index 502a1a4c9798b90579518c90aef450cda7fc9ef7..79a3e7290065213eb4271f006a01fc4344d359e3 100644
--- a/njuthesis.dtx
+++ b/njuthesis.dtx
@@ -232,12 +232,16 @@ through XeTeX.
 % \date{Released 2021-09-13}
 %
 % \maketitle
+%
+% \begin{abstract}
+% 鍗椾含澶у瀛︿綅璁烘枃\hologo{LaTeX}妯℃澘鍩轰簬鏈鐢熼櫌鐨勮鏂囨挵鍐欒鑼冨埗浣滐紝鍚屾椂鍙傝€冪爺绌剁敓闄㈡彁渚涚殑纭曞＋銆佸崥澹浣嶆潗鏂欏寘锛岀敤浜庣敓鎴愮鍚堝崡浜ぇ瀛﹀浣嶈鏂囨帓鐗堣姹傚拰鐩稿簲鐨勫浗瀹惰鑼冦€佽涓氭爣鍑嗙殑瀛︿綅璁烘枃锛屾棬鍦ㄤ负鍚屽鎻愪緵姣曚笟璁烘枃涔﹀啓鐨勬柟渚裤€�
+% \end{abstract}
+%
 % \tableofcontents
 %
 % \EnableDocumentation
 %^^A \DisableDocumentation
 % 
-%<*class>
 % \begin{documentation}
 %
 %
@@ -360,6 +364,7 @@ through XeTeX.
 % \section{\pkg{njuthesis} implementation}
 %
 %    \begin{macrocode}
+%<*class>
 \LoadClass[
   a4paper,
   twoside,
@@ -529,7 +534,6 @@ through XeTeX.
 %
 % mandatory and optional arguments are, and so forth.
 %    \begin{macrocode}
-\RequirePackage{expl3}
 \RequirePackage{fontspec}
 \RequirePackage[    
     top=2.5cm,
@@ -1829,6 +1833,7 @@ through XeTeX.
     {KEYWORDS{:}}~~{#1}%
   }
 }
+%</class>
 %    \end{macrocode}
 %
 %
@@ -1837,4 +1842,3 @@ through XeTeX.
 % \end{implementation}
 %
 % \PrintIndex
-%</class>