string(249) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BB%80%E4%B9%88%E5%B7%A5%E4%BD%9C%E8%87%AA%E7%94%B1%E5%BA%A6%E8%BE%83%E9%AB%98 => Failed to connect to 125.88.227.171 port 38062: Connection refused"
什么工作自由度较高
