remove hidden class for zh-CN

1 files changed, 0 insertions, 34 deletions

diff --git a/files/zh-cn/web/javascript/reference/global_objects/math/index.html b/files/zh-cn/web/javascript/reference/global_objects/math/index.html
index 3064bc3893..ae08c53771 100644
--- a/files/zh-cn/web/javascript/reference/global_objects/math/index.html
+++ b/files/zh-cn/web/javascript/reference/global_objects/math/index.html
@@ -127,40 +127,6 @@ translation_of: Web/JavaScript/Reference/Global_Objects/Math
  <dd>返回一个数的整数部分，直接去除其小数点及之后的部分。</dd>
 </dl>
 
-<div class="hidden">
-<div class="note">
-<p>已被移除的内容：</p>
-</div>
-
-<h2 id="拓展_Math_对象">拓展 <code>Math</code> 对象</h2>
-
-<p>As with most of the built-in objects in JavaScript, the <code>Math</code> object can be extended with custom properties and methods. To extend the <code>Math</code> object, you do not use <code>prototype</code>. Instead, you directly extend <code>Math</code>:</p>
-
-<pre>Math.propName = propValue;
-Math.methodName = methodRef;</pre>
-
-<p>For instance, the following example adds a method to the <code>Math</code> object for calculating the <em>greatest common divisor</em> of a list of arguments.</p>
-
-<pre class="brush: js">/* Variadic function -- Returns the greatest common divisor of a list of arguments */
-Math.gcd = function() {
-    if (arguments.length == 2) {
-        if (arguments[1] == 0)
-            return arguments[0];
-        else
-            return Math.gcd(arguments[1], arguments[0] % arguments[1]);
-    } else if (arguments.length &gt; 2) {
-        var result = Math.gcd(arguments[0], arguments[1]);
-        for (var i = 2; i &lt; arguments.length; i++)
-            result = Math.gcd(result, arguments[i]);
-        return result;
-    }
-};</pre>
-
-<p>试试运行下面的代码：</p>
-
-<pre class="brush: js">console.log(Math.gcd(20, 30, 15, 70, 40)); // `5`</pre>
-</div>
-
 <h2 id="规范">规范</h2>
 
 <table class="standard-table">