on.cnn.com/politics; curl -sL -o /dev/null -w &#34;%{http_code}\n&#34; http://edition.cnn.com/sport; curl -sL -o /dev/null -w &#34;%{http_code}\n&#34; http://edition.cnn.com/health&#39;
404
200
200
</code></pre><p>向 <a href=https://edition.cnn.com/politics>edition.cnn.com/politics</a> 发送请求会返回 <em>404 Not Found</em> ，然而向
<a href=https://edition.cnn.com/sport>edition.cnn.com/sport</a> 和
<a href=https://edition.cnn.com/health>edition.cnn.com/health</a> 发送请求，会像我们预�