php Curl failed when requesting Baidu's specific search page

Question

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://www.baidu.com/s?ie=utf-8&wd=lkj");

curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$output = curl_exec($ch);
echo $output;
curl_close($ch);
?>

Please help me find out where the problem is